System for processing bone stock including a bone cleaning head, a bone milling head and base that powers both the cleaning head and the milling head

ABSTRACT

A system for cleaning bone that includes a base unit with a motor, a cleaning head with a cleaning element and a mill head with a mill element. Both the cleaning head and the mill head are designed to be coupled to the base unit. Both the cleaning element and mill element have features that facilitate their coupling to the motor. When the cleaning head is attached to the base unit, a motor in the base unit rotates the cleaning element to remove soft tissue from the bone so as to clean the bone. The mill element is placed on the base unit and the cleaned bone placed in the mill head. The actuation of the base unit motor results in the actuations of the mill element. The actuation of the mill element converts the cleaned bone into bone chips.

RELATIONSHIP TO EARLIER FILED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/462,120 filed 2 May 2012, now U.S. Pat. No. 9,370,436. U.S. patentapplication Ser. No. 13/462,120 is a continuation of PCT Application No.PCT/US/2010/055646 filed 5 Nov. 2010. PCT Application No.PCT/US/2010/055646 is a non-provisional of U.S. Provisional App. No.61/258,667 filed 6 Nov. 2009. The contents of the above-listed priorityapplications are explicitly incorporated herein by reference.

FIELD OF THE INVENTION

This invention is directed to a system that first cleans bone stock and,once the bone stock is cleaned, mills the bone to form bone chips.

BACKGROUND OF THE INVENTION

There are a number of different surgical procedures in which chip-sizedbone is used as filler adjacent other sections of bone. For example, ina spinal fusion procedure, it is a known practice to place a compoundformed out of milled bone around the rods used to hold adjacent vertebrain alignment. This compound serves as a lattice upon which the tissuesforming the vertebra grow so as to form a foundation of bone around therods. This foundation distributes the load imposed on the rods. Bonechips are also used as filler and/or growth formation lattice inorthopedic surgical procedures and other procedures such asmaxillofacial procedures.

Bone chips are used as a filler/growth formation lattice in theseprocedures because the material, the proteins from which the bone isformed, serves as make-up material from which the blast cells of theadjacent living bone cells form new bone.

The ideal source of stock for bone chips is the patient into which thebone chips are to be packed. This is because the patient's own bone, owntissue, is less likely to be rejected by the patient's immune systemthan donor bone. Accordingly, in a procedure in which bone chips arerequired, the bone stock often harvested from one of the patient's bonesafford to lose a small section of bone, typically between 0.25 and 3cm³. Bone that is removed from the patient for transplant into anotherpart of the patient is referred to as autograft bone.

Once the bone is harvested, it is cleaned. After cleaning, the bone ismilled to form chips. The Applicant's Assignee's U.S. Patent Pub. No. US2009/011735 A1/PCT Pub. No. WO 2009/061728 A1, BONE MILL INCLUDING ABASE AND A MILL HEAD SEPARATE FROM THE BASE, THE MILL HEAD INCLUDING AREMOVABLE CATCH TRAY, the contents of which are explicitly incorporatedherein by reference, discloses a bone mill capable of converting bonestock into bone chips. This bone mill includes a base with a motor. Amill head, that contains the bone milling components, is removablyattached to the base. When the head is attached to the base, the motorengages at least one of the milling components. Actuation of the motorresults in a like actuation of the milling component. This results ofconversion of bone stock into bone chips.

The bone mill of the incorporated by reference publication is understoodto perform a more than adequate job of milling bone stock into bonechips. Nevertheless, prior to this process, it is still necessary toclean the bone to remove ligaments and other tissue that are notsuitable stock for forming bone chips. Presently, surgical personnelperform this task manually using curettes, rongeurs, brushes and/orcobbs. It may take 15 minutes or more for surgical personnel to performthis process.

Moreover, to perform the cleaning process, the surgical personnel mayneed to firmly grasp the bone. Exerting such force on the bone may causetearing of the gloves worn by the surgical personnel. Such tearing couldresult in the possibility that skin of the surgical personnel may comeinto direct contact with the bone. This contact can result incontamination of the bone.

SUMMARY OF THE INVENTION

This invention is related to a new and useful system for first cleaningbone and, once the bone is cleaned, milling the bone to form bone chips.

One version of the system of this invention includes: a base unit; acleaning head; and a mill head. Internal to the base unit is a motor.The base unit also includes components for releasably holding first thecleaning head and then the mill head. Internal to the cleaning head isat least one cleaning element. In some embodiments, the cleaning elementis a moveable brush, a rotating grater, and/or a rotating fluted screw.Attached to the cleaning element are features that releasably couple thecleaning element to the base unit motor. Internal to the mill head is amoveable mill element. The mill element is designed to, when actuated,mill bone stock into bone chips. The mill element includes features forreleasably coupling the mill element to the base unit motor.

The system of this invention is employed to convert harvested bone stockinto bone chips by first coupling the cleaning head to the base. Theharvested bone stock is placed in the cleaning head. The base unit motoris actuated to cause a like actuation of the cleaning head cleaningelement. The movement of the cleaning element against the bone stockremoves the ligaments, muscle, connective tissue and other debrismaterial from the surface of the bone stock.

Once the bone stock is cleaned, the cleaning head is removed from thebase unit. The mill head is fitted to the base unit. The bone stock isplaced in the mill head. The base unit motor is actuated cause a likeactuation of the mill element. Actuation of the mill element convertsthe bone stock into bone chips suitable for implantation into thepatient.

The integrated system of this invention includes components for bothcleaning and milling the bone stock. By having the mechanized cleaninghead perform the cleaning process, the need for operating room personnelto perform this task is eliminated. In many situations, the cleaninghead cleans bone stock in less time than it takes an individual toperform the same task.

Still another advantage of the integrated system of this invention isthat a single unit, the base unit, provides the motive power needed toactuate the cleaning element internal to the cleaning head and the millelement internal to the mill head. The need to provide essentiallyduplicative power units, one for each head, is eliminated.

In an alternative version of the invention, a single head is attached tothe base. The head has a module with a brush for cleaning the bone.Below the cleaning module, the head has a mill module. Internal to themill module are components for milling the bone stock into chips. Themill module is dimensioned to be removably coupled to the base unit. Themodules have components that, when the head is attached to the baseunit, couple the brush and moving mill element to the motor internal tobase unit. In one embodiment of this version of the invention, thecleaning module is moveable relative to the mill module.

The alternative version of the invention is prepared for use by couplingthe head to the base. The harvested bone stock is placed in the cleaninghead. The base unit motor is actuated. The motor drives the brushinternal to the head so as to clean the bone. Once the bone is cleaned,the cleaning module is moved to a position in which it is directed tofeed port integral with the mill module. The cleaned bone is dischargedfrom the cleaning module into the mill module. Once the bone is sotransferred to the mill module, the motor is again actuated. As a resultof this actuation of the motor, the consequential actuation of the millelement converts the previously cleaned bone stock into bone chips.

An assembly for cleaning bone stock includes a base. A shell issupported by the base for defining a void space for receiving the bonestock to be cleaned. At least one cleaning element is disposed in thevoid space. A drive assembly is coupled to the at least one cleaningelement to actuate the at least one cleaning element to clean the bonestock. In some embodiments, the cleaning element is a rotating brush, arotating grater, and/or a rotating fluted screw.

A further advantage of the above alternative versions of the inventionis that once the bone stock is placed in the cleaning head, the need forsurgical personnel to handle bone is substantially eliminated.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is pointed out with particularity in the claims. The aboveand further features and advantages of this invention are betterunderstood by the following detailed description taken in conjunctionwith the following drawings in which:

FIG. 1 depicts the basic components of the integrated system forcleaning and milling bone of this invention;

FIG. 2 is a perspective view of the base unit;

FIG. 3 is a cross sectional view of components internal to the baseunit.

FIG. 4 is a perspective view of the top of the base unit;

FIG. 5 is a schematic and block diagram of the memories internal to thebase unit and cleaning head and the components over which data are readfrom and written to these memories;

FIG. 6 is a simplified block diagram of the circuits internal to thecontrol console;

FIG. 7 is an exploded view of the components forming the cleaning head;

FIG. 8 is a perspective view of the lower shell of the cleaning head;

FIG. 9 is a view of the bottom surface of the lower shell of thecleaning head;

FIG. 10 is a plan view, looking down, of the cleaning head lower shell;

FIG. 11 is a cross sectional view of the cleaning head upper shell;

FIG. 12 is a perspective view of the bottom surface of the substrate ofthe cleaning head lower brush;

FIG. 13 is a side view of the cleaning head lower brush;

FIG. 14 depicts data fields in the memory of the RFID fitted to thecleaning head lower brush substrate;

FIG. 15 is a side view of the cleaning head upper brush;

FIG. 16 is an exploded view of the system mill head;

FIG. 17 is a perspective view of the bottom shell of the mill head;

FIG. 18 is a plan view of the mill element, here a cutting disc,internal to the mill head;

FIGS. 19A through 19C, when assembled together, form a flow chart of thesteps performed to both clean bone stock and convert the bone stock intochips using the system of this invention;

FIG. 20 is an exploded view of an alternative cleaning head of thisinvention;

FIG. 21 is a cross sectional view of the upper shell and shaft of themill head of FIG. 20;

FIG. 22 is a plan view looking upwardly, of the bottom of the uppershell, shaft and spacer ring of the mill head of FIG. 20;

FIG. 23 is a perspective view of the underside of the lower brushsubstrate of the mill head of FIG. 20;

FIG. 24 is a perspective view of the drive assembly of the mill head ofFIG. 20;

FIG. 25 is a perspective view of the drive shaft of the mill head ofFIG. 20;

FIG. 26 is an exploded view of the integrated cleaning and mill head ofthis invention;

FIG. 27 is a side plan view of the lower plate of the head of FIG. 26;

FIG. 28 is a perspective view of the upper plate of the head of FIG. 26;

FIG. 29 are a flow chart of the process steps executed during theoperation of the head of FIG. 26;

FIG. 30 is an exploded view of an alternative brush of the system ofthis invention;

FIG. 31 is a side plan view of the substrate/superstrate of the brush ofFIG. 30.

FIG. 32 is a exploded view of a second alternative cleaning head of thisinvention;

FIG. 33 is a top plan view of the base of the alternative cleaning headof FIG. 32;

FIG. 34 is a cross sectional view along line 34-34 of the base of FIG.33;

FIG. 35 is a bottom plan view of the cap of the cleaning head of FIG.32;

FIG. 36 is a perspective view of the bottom of the cap of the cleaninghead of FIG. 32;

FIG. 37 depicts how the cleaning head of FIG. 32 is mated to thecomplementary mill head to facilitate the transfer of cleaned bone stockfrom the cleaning head to the mill head;

FIG. 38 is a cross-sectional perspective view of a third alternativecleaning head of this invention comprising a plurality of rotatingfluted screws and a central agitator;

FIG. 39 is an exploded view of the alternative cleaning head of FIG. 38;

FIG. 40 is cross-sectional view of one of the rotating fluted screws ofthe alternative cleaning head of FIG. 39;

FIG. 41 is an exploded view of the rotating fluted screw of FIG. 40;

FIGS. 42 and 43 are top and bottom perspective views of the spindle usedto drive the rotating fluted screws of the alternative cleaning head ofFIG. 38;

FIG. 44 is a perspective view of an axle on which the rotating flutedscrews rotate in the cleaning head of FIG. 38;

FIG. 45 is a perspective view of shaving block of the alternativecleaning head of FIG. 38;

FIG. 46 is a perspective view of a plug for the alternative cleaninghead of FIG. 38;

FIG. 47 is a partial perspective view illustrating the void space andshaving block with rotating flute screw of the alternative cleaning headof FIG. 38;

FIG. 48 is a cross-sectional perspective view of a fourth alternativecleaning head of this invention comprising a rotating inner basket and arotating brush;

FIG. 49 is an exploded view of the alternative cleaning head of FIG. 48;

FIG. 49A is a partial perspective view an alternative gear train for thealternative cleaning head of FIG. 48;

FIG. 50 is an exploded view of a fifth alternative cleaning head with arotating grater and a plunger;

FIG. 51 is a cross-sectional view of the alternative cleaning head ofFIG. 50;

FIG. 51A is a top perspective view of the rotating grater of FIG. 50;

FIG. 52 is an exploded view of a sixth alternative cleaning head of thisinvention comprising a rotating grater and an impingement plate;

FIG. 53 is a top perspective view of the alternative cleaning head ofFIG. 52 illustrating the rotating grater and the impingement plate;

FIG. 54 is an exploded view of a seventh alternative cleaning head ofthis invention comprising a rotating grater, rotating fluted screw, andplunger;

FIG. 55 is a cross-sectional view of the alternative cleaning head ofFIG. 54; and

FIG. 56 is a top perspective view of the alternative cleaning head ofFIG. 54 illustrating the rotating grater and rotating fluted screw.

DETAILED DESCRIPTION I. Overview

FIG. 1 illustrates the basic components of integrated system 50 of thisinvention for cleaning and milling bone stock. System 50 includes a baseunit 52. Internal to the base unit 52 is a motor 54, (FIG. 3). Acleaning head 56 is removably attached to the base unit 52. Internal tothe cleaning head are brushes 58 and 59 (FIG. 7). Cleaning head 56 isconfigured so that, when the cleaning head 56 is attached to the baseunit 52, brush 58 is connected to the motor 54 so as to be actuated bythe motor 54. The system 50 includes a mill head 60 that, like cleaninghead 56, is configured to be removably attached to the base unit 52. Amill element 62 (FIG. 16), sometimes referred to as a cutting device, ismoveably mounted inside, the mill head 60. Mill element 62 includesfeatures that, when the mill head 60 is mounted to the base unit 52couple the mill element to the motor 54.

Also part of system 50 is a control console 66. Control console 66supplies the energization signals to the motor 54 that actuate the motor54. Cable 67 connected between the base unit 52 and console 66 containsthe conductors (not illustrated) over which energization signals aresupplied from the console 66 to the motor 54.

System 50 of this invention is used by coupling the cleaning head 56 tothe base 52. Harvested bone stock is placed in the cleaning head 56. Themotor 54 is actuated so as to result in a like actuation of brush 58.The action of the brush 58 against the bone stock strips the soft tissueand other debris from the bone stock. The cleaning head 56 is removedfrom the base unit 52 and the mill head 60 is fitted to the base unit.The cleaned bone stock is placed in the mill head 60. Base unit motor 54is again actuated so as to result in a like actuation of the millelement 62. As a consequence of the actuation of the mill element 62,the cleaned bone stock is milled into bone chips suitable forimplantation into the patient.

II. Base Unit and Control Console

The base unit 52, now described by reference to FIGS. 2 and 3, includesa circular foot 70. A leg 72 having a circular cross section extendsupwardly from foot 70. Leg 72 is tubular in shape. A pedestal 74 isdisposed on top of leg 72. The pedestal 74 tapers outwardly from the leg72. Pedestal 74 has a generally circular top surface 76. The pedestal isfurther formed to have a lip 78 that extends upwardly around the outerperimeter of the top surface. The outer circumference of lip 78, whichis the outer circumference of the pedestal 74, is less than that of thecircumference of foot 70 and larger than that of leg 72. Pedestal 74 isfurther formed so as to have an opening 80 in the center of top surface76.

While pedestal 74 is generally circular in shape, as best seen in FIG.4, a notch 83 extends inwardly from the outer perimeter. Notch 83 thusforms a break in lip 78. In the illustrated version of the inventionnotch 83 extends to center opening 80. The pedestal is further formed toinclude a number of arcuately spaced apart teeth 84. Each tooth 84extends upwardly from the outer perimeter of the pedestal top surface 76adjacent lip 78. Pedestal 74 is further formed to have a rectangularopening 85 that is spaced away from both center opening 80 and notch 84.

Two retention arms 86, seen best in FIGS. 3 and 4, are pivotally mountedto the pedestal 74. Retention arms 86 are mounted to the pedestal incutouts formed in the lip 78, (cutouts not identified). Each retentionarm has a finger 88 that, when the arm is at rest, extends over aportion of the pedestal top surface 76. When the arms 86 are sopositioned, the arms are in the “locked” state. Each retention arm 86has a tab 89 located below the pedestal 74. By depressing the tab 89inwardly, towards the underside of the pedestal 74, the arm 86 ispivoted outwardly so as to pivot the associated finger 88 away from itsposition over the pedestal top surface 76. When the arms 86 are sopositioned, the arms can be considered in the “release” state. A spring90 disposed between inner surface of the pedestal 74 and each arm 86,normally holds each arm in the locked state.

Referring to FIGS. 3 and 4, motor 54 includes a shaft 96 also disposedin the center hollow of leg 72. Shaft 96 extends upwardly towardpedestal center opening 80. A gear head at the top of shaft 96 (gearhead not identified) engages a gear train 98 disposed in leg 72 abovethe motor 54. Gear train 98 steps down the rotational of speed of therotational moment output by motor shaft 96. The gear assembly 98 has anoutput shaft 102 disposed in the pedestal center opening 80 below thetop surface 76. Output shaft 102 is tubular in shape. Shaft 102 isformed to have two diametrically opposed oval openings 103 (one shown inFIG. 2) that extend longitudinally along the shaft.

In some versions of the invention, motor 54 and gear train 98 arecollectively provided so that the gear train output shaft 102 can rotateat speeds between 100 and 500 RPM. These speeds are the under load speedwhen bone stock is disposed in either the cleaning head 56 or mill head60. For reasons apparent below, the motor 54 and gear train 98 aredesigned to drive the output shaft 102 in an oscillatory pattern.

A drive spindle 104 is disposed in output shaft 102. The drive spindle104 includes a stem 106. Above stem 106, spindle 104 is shaped to have adisc-shaped head 108. A number of different components extend upwardlyfrom the top surface of the spindle head 108. One of these components isan alignment pin 110. The alignment pin 110 is coaxial with thelongitudinal axis of the spindle 104 and extends upwardly from thecenter of the head 108. Pin 110 is shaped so that the lower portion, theportion that extends upwardly from the spindle head 108, has acylindrical shape. The top portion of alignment pin has a shape of acone with a flattened tip. (The individual sections of alignment pin 110are not identified.)

Four equiangularly spaced apart alignment teeth 112 also extend upwardlyfrom the top surface of the spindle head 108. Teeth 112 are locatedaround the outer perimeter of the spindle head 108. The arcuate outersurfaces of teeth 112 are flush with the outer surface of the spindlehead 108. Each tooth 112 has a pair of inwardly tapered side surfacesand an arcuate inner surface. (Surfaces not identified.) Teeth 112 donot extend as far above the spindle head 108 as does alignment pin 110.

Spindle 104 is dimensioned and positioned so that stem 106 is slidablymounted in the bore that extends through the gear assembly output shaft102, (bore not identified). A pin 114 extends through a bore 107 in thespindle stem 106. The opposed ends of the pin 114 are seated indiametrically opposed openings 103 formed in shaft 102. Pin 114 holdsthe drive spindle 104 to the shaft 102 so that the spindle rotates inunison with the shaft and is able to move longitudinally relative to thegear assembly 98.

A spring 118 is disposed in the output shaft 102 below spindle stem 106.Spring 118 is a wave spring. One end of spring 118 is seated on theannular step internal to the output shaft 102 (step not identified). Theopposed end of spring 118 is disposed against the bottom end of spindlestem 106. Spring 118 exerts an upward bias on spindle stem 106. Thisforce, which can be overcome by the application of manual force,normally displaces the spindle 104 so that the head 108 is urged awayfrom the pedestal top surface 76.

A spring biased, normal open press button switch 120 is mounted to thebase unit foot 70 (FIG. 2). A socket 122, shown symbolically in FIG. 5,receives cable 67 from control console 66. Internal to foot 70 is acircuit board 124 (FIG. 3). Mounted to the circuit board 124 arecomponents that function as the interface between switch 122 and theconductors that extend to socket 122. Also disposed on circuit board 124are components that function as interfaces between the power conductorsinternal to cable 67 and the conductors that extend to the windings ofthe motor 54. The specific structure and configuration of thesecomponents as well as of the conductors that extend to motor 54, switch120 and socket 122 are neither illustrated or part of this invention.

Also disposed on circuit board 124 is a non-volatile memory 126 seen inFIG. 5. Memory 126 contains data describing the base unit 52. These datainclude data identifying the type of device; here, that the device is abone cleaner/bone mill base unit. These data also contain data usefulfor supplying energization signals to the motor 54. These latter datainclude data indicating the speed range of the motor and the currentsthe motor should draw. A more complete list of the data that may becontained in memory 126 can be found in the Applicants' Assignee's U.S.Pat. No. 6,017,354, INTEGRATED SYSTEM FOR POWERED SURGICAL TOOLS, thecontents of which is explicitly incorporated herein by reference. In oneversion of the invention, memory 126 is a radio frequency identificationdevice (RFID) and is identified as such in FIG. 5. An antenna (coil) 125is connected to the memory 126. A coil 127 is connected to theconductors 123 that extend from the socket 122. Signals between thecontrol console 66 and the memory 126 are inductively exchanged betweenmemory coil 125 and base unit coil 127.

Base unit 52 also includes an assembly for reading non volatile memoriesintegral with the cleaning head 56 and mill head 60. This assemblyincludes a coil 130. Coil 130 is disposed in pedestal opening 85. Coil130 is encased in a block 132 (FIG. 4) disposed in opening 85. Coil 130is series connected to coil 127. Block 132 is formed from materialpermeable to RF energy and that can withstand the rigors of autoclavesterilization.

FIG. 6 is a block diagram of some of the basic assemblies internal tothe control console 66. One of these assemblies is the power supply 160.The power supply 160 converts the line signal into a DC voltage suitablefor application to the windings internal to the base unit motor 54.Power supply 160 also produces AC and DC voltages by the othercomponents internal to the control console and internal to the controlconsole 66 and base unit 52. For reasons of simplicity, the only theconnection shown out of the power supply 160 is the VDC that is appliedto the motor windings. This VDC signal is applied to a motor driver 162.Motor driver 162 selectively ties the individual windings of the motorto either the VDC signal or ground. This is the commutation the currentflowed through the motor windings (windings not illustrated). The motordriver 162 is connected to cable 67 by a socket 163 integral with theconsole 66.

Motor driver 162 selectively ties the motor windings to the VDC signalor ground based on both feedback signals from the windings and commandsignals from a display controller 164. The display controller 164generates command signals that indicate the speed at which the motorshould run, the maximum currents the windings should draw and thesequence in which the voltages are applied across the windings. Theselast data are used to regulate the direction in which the motor shaftrotates. Display controller 164 generates these command signals based onboth user entered data and stored data that indicates thecharacteristics of the energization signals that are to be applied tothe motor.

The data indicating the characteristics of the energization signals thatare to be applied to the base unit motor 54 are retrieved from differentsources. These data may be stored in memory 166 internal to the controlconsole 66. These data may be retrieved from the memory 126 internal tothe base unit 52. Alternatively, these data may be retrieved from amemory 270 internal to the cleaning head 56 (FIG. 5) or a memory 320(FIG. 17) internal to the mill head 60.

To read the data in the base unit memory 126, cleaning head memory 270and mill head memory 320 control console 66 includes a RFID interface168. RFID interface 168 is connected to the display controller 164. Inresponse to command signals from the display controller 164, the RFIDinterface sends read request signals to the complementary memories. Inresponse the read request, the memory 126, 270 or 320 writes out thestored data. Interface 168 converts these data signals into digitalsignals that are interpreted by the display controller 164.

Control console 66 also includes a touch screen display 174. Displaycontroller 164 generates both data images and images of command buttonsfor presentation on the display 174. The display controller 164 receivesthe signals when an individual presses the display buttons. In responseto the depression of the buttons, display controller 164 generates theappropriate commands to cause the user-requested operation of the baseunit motor 54.

A more detailed understanding of the structure of the control console 66can be found in the Applicants' Assignee's U.S. Pat. No. 7,422,582,CONTROL CONSOLE TO WHICH POWERED SURGICAL HANDPIECES ARE CONNECTED, THECONSOLE CONFIGURED TO SIMULTANEOUSLY ENERGIZE MORE THAN ONE AND LESSTHAN ALL OF THE HANDPIECES, the contents of which are explicitlyincorporated herein by reference.

III. Cleaning Head

As seen by reference to FIG. 7, the cleaning head includes opposed lowerand upper shells 192 and 194, respectively, that are releasably coupledtogether. A lower brush 58 is rotatably and removably disposed in thelower shell 192. An upper brush 59 is disposed in the upper shell 194.While the upper brush 59 is removably and, to a limited degree moveablymounted with regard to the upper shell, the upper brush does not rotate.A cap, (not illustrated) may be removably fitted over the exposed top ofupper shell 194.

Lower shell 192 is formed from aluminum or other material that canwithstand repetitive autoclave sterilization. As seen best in FIGS. 8, 9and 10, the lower shell is shaped to have a disc shaped base 206. Base206 has an outer diameter that allows the shell 192 to be slip fitted inthe void space immediately above pedestal top surface 76 within lip 78.Shell base 206 has a center opening 208. Center opening 208 has adiameter that is approximately 2 mm larger than the diameter of spindlehead 108. Four equiangularly spaced apart notches 210 extend inwardlyand upwardly from the downwardly directed face of the shell base.Notches 210 are dimensioned so that when the cleaning head 56 is fittedto base unit 52, pedestal teeth 84 are able to seat in the notches.

Located radially outwardly from opening 208, base 206 is formed to havean annularly extending groove 212. Groove 212 is positioned so that,when the cleaning head 56 is seated in the pedestal void space 79,groove 212 extends over the space above coil 130. A hole 213 extendsupwardly from the base of groove 212.

A ring 214 is integrally formed with and extends upwardly from the outerperimeter of shell base 206. The outer diameter of ring 214 iscoincident with the outer diameter of base 206. Ring 214 defines acylindrical void space (not identified) within the lower shell 192. Theoutwardly directed face of the shell base 206 functions as the base ofthis void space. Lower shell 192 is further formed to have twoadditional notches 220 that are diametrically opposed from each other.(Only one notch 220 seen in FIG. 8.) Notches 220 extend inwardly fromthe outer cylindrical surface of the shell 192 at a location above thebottom of the shell. More particularly, shell 192 is formed so that whenthe shell is seated in pedestal void space 79 and teeth 84 are innotches 210, notches 220 are positioned so the fingers 88 integral withthe pedestal retention arms 86 can seat against the shell ring surfacesthat define the bases of the notches 220.

Lower shell 192 is further formed to have three equiangularly spacedapart slots 224 in the exposed circular, outwardly directed face of ring214. Each slot 224 has what can be generally described as a keyholeshape. That is, each slot 224 has a circular section and a section thatresembles a section of a curve that extends away from the circularsection (individual sections not identified). The width across eachcurved segment section is less than the diameter of the circularsection. More particularly, lower shell 192 is formed so that opposedledges 226 extend over the slot curved sections to provide theappearance of these sections having a width less than diameter of theslot circular sections. Below the ledges 226 the common widths of slotsis constant.

Shell base 206 is further formed to have a circular groove 230 in theoutwardly directed face of the base. Hole 213 opens into the surface ofthe base 206 that forms the base of the groove 230.

A coil 232, seen in FIG. 5, is disposed in base groove 212. Not seen isthe ring formed of PEEK, polyetherimide or other sterilizable plastic inwhich coil 232 is embedded. Accordingly, both the coil 232 and the ringare seated in groove 212 so as to be flush with the downwardly directedface of shell base 206. Conductors 234 extend from coil 232 throughshell base hole 213. Conductors 234 extend to a coil 236 seated in shellbase groove 230. Coil 236 is embedded in the same type of ring (notillustrated) in which coil 232 is embedded. Coil 236 and itscomplementary ring are seated in groove 230 so as to be flush with theadjacent outwardly directed face of shell base 206.

The cleaning head upper shell 194, now described by reference to FIGS. 7and 11, is formed from the same material from which lower shell 192 isformed. Upper shell 194 includes a circular plate 240. Plate 240 has thesame outer diameter of the lower shell 192 and functions as thesuperstructure of the upper shell 194. An annular skirt 242 formedintegrally with the plate 240, extends downwardly from the outerperimeter of the plate. The bottom surface of plate 240 and skirt 242thus define a void space 246 internal to the upper shell 194 thatextends upwardly from the outer face of the skirt to the downwardlydirected surface of plate 240.

Three equiangularly spaced apart pins 248 extend downwardly from thedownwardly directed face of skirt 242 (Only one pin 248 seen in bothFIGS. 7 and 11.) Each pin 248 has a narrow diameter stem (notidentified) and a large diameter head (not identified). The pin headsare dimensioned to pass through large diameter opening of one the lowershell slots 224 but not the narrow diameter curved section of the slot.Upper shell pins 248 are thus the fastening members that complement thelower shell slots 224 so as to removably hold the shells 192 and 194together without the aid of other fastening components. A cylindricalboss 250 formed integrally with the plate 240 extends upwardly from theexposed upper surface of the plate. Boss 250 is centered on thelongitudinal axis of the plate 240. A bore 252 extends through the plate240 and overlying boss 250. Bore 252 is centered on the longitudinalaxis of the plate 240 and boss 250. Bore 252 has a non-circular crosssectional shape. In the illustrated version of the invention, the bore252 has a cross-sectional shape that is square. A threaded bore 249extends laterally from the side of boss 250 into bore 252.

Three load pins 253 are slidably mounted in through holes 251 formed inplate 240. Holes 251 are equiangularly spaced apart from each other andlocated outwardly of shell boss 250. Each pin 254 extends into voidspace 246. A helical spring 254 is disposed around the section pin 253disposed in the shell void space 246. Springs 254 urge the pins 253toward the lower shell 192. Not seen are the heads of the pins againstwhich the springs 254 abut and the feet of the pins that prevent thepins from falling out of the holes 251.

FIGS. 12 and 13 illustrate the features of the cleaning head lower brush58. Brush 58 is formed to have disc-shaped substrate 260 formed of metalor a sterilizable plastic such as a glass-filled nylon. Substrate 260has an outer diameter that is generally at least 0.5 mm less than thediameter of the void space defined by the inner wall of lower shell ring214. Thus brush 58 is able to float, laterally shift position, withinthe lower shell 192. While the opposed upper and lower faces ofsubstrate 260 are generally planer and parallel, a number ofindentations extend upwardly from the inner face lower face of substrate260. One of these indentations is a closed-end bore 262 that is centeredover the longitudinal axis of the disc. Bore 262 has a diameter thatallows the base unit drive spindle alignment pin 110 to seat therein.Four equiangularly spaced apart notches 264 are the other indentationsthat extend upwardly from the bottom-directed face of lower brushsubstrate 260. Notches 264 are positioned so that when spindle pin 110is seated in substrate bore 262, spindle teeth 112 seat in the notches.Substrate 260 is also formed to have a single notch 266. Notch 266 ispositioned so that when lower brush 58 is seated in the lower shell 192,the notch 266 is disposed over coil 236.

Lower brush 58 includes a number of bristles 268 that extend upwardlyfrom the upwardly directed face of substrate 260. The bristles 268 areformed from a stainless steel. Bristles 268 are attached to substrate byan adhesive 267 such as an epoxy adhesive. In manufacture, adhesive 267is initially applied over upwardly directed face of substrate 260.Before the adhesive cures, the bristles 268 are planted in the adhesive267.

An RFID chip 270, illustrated in FIG. 5, is disposed in substrate notch266. RFID chip 270 functions as the memory for the lower brush 194.Attached to RFID chip 270 is a coil 271. RFID chip 270 and coil 271 areencapsulated in a plastic block 269 (shown in phantom in FIG. 5). Block269 is formed from a plastic that allows inductive signal exchangedbetween shell coil 236 and brush coil 271.

FIG. 14 illustrates different data stored in the actual memory 272internal to the RFID chip 270. The data in memory 272 include a deviceidentification field 273. The data in field 273 identifies that theassociated device is a bone cleaning brush. If there are a number ofdifferent bone cleaning brushes, the data in field 273 identifies thespecific kind of brush. A use field 274 contains data indicating whetheror not the brush is useable. It is anticipated that, owing to theexpenses associated with post-use sterilization, each brush is a useonce brush. Accordingly, field 274 may be a single bit field that isinitially set to contain data indicating that the brush 58 can be used.

Memory 272 also contains minimum, default and maximum motor speedsfields 275, 276 and 277, respectively. The data in the minimum andmaximum motor speed fields 275 and 277, respectively, indicate,respectively, the preferred minimum and maximum speeds at which the baseunit motor 54 should be driven to rotate the lower brush 58. The defaultspeed field 276 indicates that speed at which the motor is to be drivenin the event the personnel operating the system do not set any otherspeed.

A direction field 278 indicates the direction in which base unit motor54 should be driven. Typically, the data in field 278 indicates if themotor is to be driven in a single direction or in an oscillatory mode.If the motor, actually, the lower brush 58, is to be driven in a singledirection the direction of rotation is irrelevant. If the lower brush 58is to be oscillated back and forth, field 278 may include additionaldata indication through which how many degrees the brush should rotatebefore the direction of rotation is reversed.

In some versions of the invention, field 278 may contain data indicatinga sequence of rotation in which the lower brush 58 upon actuation. Onesequence may include an initial rotation of the brush through 10rotations in one direction followed by rotation in oscillatory patternwherein in each phase of the oscillation the brush rotates 2 rotations(720°) in one direction before the direction of rotation is reversed.

The upper brush 59, now described with reference to FIG. 15, includes adisc shaped superstrate 284. Superstrate 284 is formed from the samematerial from which lower brush substrate 260 is formed. The superstate284 has an outer diameter equal to the lower brush substrate 260. A post286 extends upwardly from the longitudinal center axis of superstrate284. Post 286 is dimensioned to slidably fit in upper shell bore 252.

Bristles 290 extend downwardly from the bottom facing surface ofsuperstrate 284. A layer of adhesive 288 holds the bristles 290 tosuperstrate 284.

A ball plunger 257 (FIG. 7) is fitted in upper shell bore 249. Ballplunger 257 is set to press against post 286 to prevent upper brush 59from falling out of upper shell 194. In some versions of the invention,brush post 286 is formed with a detent (not illustrated) for receivingthe plunger head.

IV. Mill Head

FIG. 16 illustrates the basic components of the mill head 60. There arebottom and top shells 302 and 304, respectively. When assembledtogether, shells 302 and 304 form the housing of the mill head 60. Millelement 62 is a disc shaped member sandwiched between shells 302 and304. Top shell 304 is formed to have an open ended feed sleeve 306. Thecenter space defined by sleeve 306 opens into the space in which millelement 62 is seated. A plunger 308 is slidably fitted in feed sleeve306.

Fitted to top shell 304 is an impingement plate 308 (shown in phantom asa rectangular bar). Impingement plate 308 is mounted to the top shell soas to be near the base of the feed sleeve and immediately above the millelement 62.

Bottom shell 302 is formed to have an opening 309 immediately bellow thefeed sleeve 306. A removably catch tray 310 is slidably fitted to thebottom shell 302. Catch tray 310 is fitted to bottom sleeve 306 toreceive bone chips discharged from mill head 60 through opening 309.

Mill head bottom shell 302, seen in FIG. 17, is generally circularlyshaped. More particularly, shell 302 is dimensioned to seat within thebase unit void space 79. Shell 302 is formed to have four equiangularlyspaced apart notches 312 that extend inwardly from the outer perimeterof the shell. Notches 312 are positioned so that when mill head 60 isseated on the base unit pedestal 74, pedestal teeth 84 seat in thenotches 312. Shell 302 has a center located opening 314 dimensioned toreceive base unit drive spindle 104.

Opening 309 extends inwardly from the perimeter of the bottom shell 302.The bottom shell 302 is further formed to have two rails 316 located onthe opposed sides of opening 309. Rails 316 are dimensioned to allow thecatch tray to be slidably held to the shell 302 below opening 309. Forreasons not relevant to the present invention, the rails 316 are shapeddifferently from each other.

An RFID chip 320, shown as a phantom rectangle in FIG. 17, is embeddedin bottom shell 302. A complementary coil 322, also shown in phantom isattached to RFID chip 320 and also embedded in shell 320. Coil 322 islocated within the shell 302 so that when the mill head 60 is disposedon the base unit 52, the coil 322 is disposed over base unit coil 130.The memory of RFID 320 contains data similar to that contained incleaning head RFID 270. Specifically, there is a data field in whichdata identifying the type of device, a mill head 56, are stored. Thereis also at least one data field indicating the speed at which the baseunit motor 54 should operate when the mill head 56 is attached.Typically, the mill element 62 is intended to be driven at a singlespeed. Accordingly, in a number of versions of the invention, RFID 320only contains a single data field containing data indicating the speedat which mill element 62 is to be rotated. Also, the mill element 62 istypically only rotated in a single direction. Accordingly, RFID 320likewise typically does not contain any data containing instructionsregarding a forward/reverence sequence for driving the mill element 62.

Returning to FIG. 16, it can be seen that top shell 304, like bottomshell 302 is generally disc shaped. The top shell 304 is further shapedto have the same outer diameter as the bottom shell 302. Collectively,shells 302 and 304 are shaped so that when the mill head 60 is seated inbase unit void space, the outer face of the top shell 304 is slightlyabove the pedestal lip 78. The top shell 304 is formed so as to have twodiametrically opposed notches 328; one notch seen in FIG. 16. Notches328 are positioned so that when the mill head 60 is fitted to the baseunit pedestal 74, the base unit retention arm fingers 88 are able toseat in the notches 328.

Mill element 62, seen best in FIG. 18, may be formed from metal such as410 Stainless Steel. In the illustrated version of the invention, themill element 62 is generally in the form of a planar disc. In theillustrated version of the invention, mill element 62 is sometimesreferred to as a cutting disc. Collectively, the components forming themill head 60 are dimensioned so that the mill element 62 can engage inlateral movement, as well as some up-and-down movement, within the millhead housing.

The mill element 62 is further shaped to have a center-located hole 332.Hole 332 is dimensioned to receive the alignment pin 110 integral withthe base unit drive spindle 104. Located around hole 332, mill element62 is formed to have four equiangularly shaped apart openings 334. Eachopening 334 is shaped to receive a separate one of the teeth 112integral with spindle 104. Accordingly, openings 334 are arcuatelyshaped. The circle defined by the outer circumference of openings 334 isless than bottom shell opening 314.

The mill element 62 is further formed to have a number of cuttingscallops 336. Integral with and longitundally axially aligned with eachcutting scallop 336, the cutting disc has a through opening 338. Moreparticularly, the mill element 62 is formed so that each cutting scallop336 extends above the adjacent top surface of the element. The scallops336 are milled to define a cutting edge 340 that forms a perimeter ofthe adjacent opening 338.

Impingement plate 308 is formed from material against which bone stockcan be pressed without causing the fracture of the plate. In someversions of the invention, this material is 304 stainless steel. Theimpingement plate 308 is fitted to the mill head top shell 304 so as tobe located to one side of the opening through feed sleeve 306 and so asto be above the mill element 62. Impingement plate 308 is furtherpositioned so that, as the mill element 62 rotates, first an elementopening 338 followed by the cutting edge-defining scallop 336 thatdefines the opening rotates towards and under the plate 308.

V. Operation

System 50 of this invention is used to clean and mill bone that isharvested to serve as stock from which bone chips are formed. To preparethe system for use, a lower brush 58 is fitted in lower shell 192 and anupper brush 59 is fitted in upper shell 194. The harvested bone isplaced against the lower shell bristles 268. The upper shell 194 iscoupled to the lower shell so that that harvested bone stock issandwiched between the lower and upper brushes 58 and 59, respectively.To couple the shells 192 and 194 together, the upper shell pins 248 arerotating held in the lower shell slots 224. Collectively, these stepsare called out as step 350 in FIG. 19A.

Once the two shells 192 and 194 are coupled together, the post 286 maybe pressed downwardly to unlock the post from the ball plunger 257. Thisallows upper brush 59 to move longitudinally within cleaning head 56.Pins 253, which are urged against the upper brush superstrate 284 bysprings 254, provide a force in addition to gravity that presses theupper brush bristles 290 against the bone to be cleaned. It should beunderstood that owing to the relative dimensions of the lower shell 192and brush 58, the brush may shift laterally within the shell.

The cleaning head 56 is then mounted to base unit 52, step 351. Moreparticularly, the cleaning head 56 is positioned so that the head lowershell 192 is positioned on pedestal top surface 76 so that pedestalteeth 84 seat in shell notches 210. Base unit retention arms 86 are setso that fingers 88 seat in pedestal notches 220. This seating of theretention arm fingers 88 in the lower shell notches 220 is what holdscleaning head 56 to the base unit 52. The seating of base unit teeth 84in cleaning head notches 210 prevent rotation of the head 56 relative tothe base unit 52.

As part of the seating of the cleaning head 56 on the base unit 52, step351, drive spindle 108 extends through the lower shell opening 208. Thespindle alignment pin 110 seats in lower brush opening 262. The seatingof pin 110 in opening 262 may laterally shift the lower brush 58 in thelower shell 192 so that substrate openings 264 define a circle that isaligned over spindle drive teeth 112.

Also as part of preparing the system 50 for use, the base unit 52 isconnected by a cable 67 to control console 66. The control console 66 isactuated. (Steps not illustrated.)

Once the system is actuated, the control console display controller 164,through RFID interface 168, reads the contents of the base unit memory126, step 354 of FIG. 19A. Base on unit-identifying data in memory 126,in step 324, display controller 164 determines that the device attachedto control console 66 is a bone cleaner/bone mill base unit 52, step356. Based on this determination, display controller 164, as part ofstep 356, recognizes that it must determine the type of head 56 or 60attached to the base unit before it determines the characteristics ofthe energization currents that should be applied to the base unit motor54. Accordingly, in a step 358 the display controller 164, through theRFID interface 168, reads out the data in the cleaning head brush RFID270, step 360. These data are read as a consequence of the inductivesignal exchange between base unit coil 130, shell coils 232 and 236 andbrush coil 271.

It should be understood that there is always the possibility that eithercleaning head 56 or mill head 60 once attached to the base unit 52 willbe removed. Therefore, periodically throughout the time the base unit 52is attached to the control console 66, the display controller 164 willrequest the RFID interface to conduct a basic interrogation to determineif the head 56 or 60 previously attached to the base unit 52 is stillattached. This integration process often involves the outputting of a bythe RFID interface 168 of a request that any attached RFID write backsome basic identifying data. These data, if written back to the displaycontroller 164 indicate that the device that was attached to the baseunit 52 is still attached. Thus, as long as the base unit is connectedto the console 66, data are written from the base unit memory 126 backto the console. The same read out of data occurs as long as the millhead 56 is attached to the base unit 52.

The absence of responses to these write request is interpreted by thedisplay controller 164 that the base unit 52 is no longer attached tothe console or the system component, the cleaning head or the mill head,is not longer attached to the base unit. While not represented in theflow chart of FIGS. 19A through 19C, it should be understood that thesebasic interrogation processes are repetitively executed as long as thecontrol console 66 is turned on and connected to the base unit 52.

Based on the data the brush RFID 270, display controller configuressystem 50 for operation to clean the bone, step 362. Step 362 involvesgenerating a sequence of instructions that indicate the speed anddirection in which the motor should rotate. As part of step 362, thedisplay controller 164 also causes to be presented on the display 174information about the state of the system 50. These data include dataindicating that the attached device is bone cleaning head, the speedrange at which the base unit 54 should operate as well as the defaultoperating speed. The surgical personnel can, if they want to, in a step364, set the system for operating based on personal preferences of thecharacteristics of the bone disposed in the cleaning head 56.

The surgical personnel then actuate the cleaning head by depressing baseunit button 120, (step not illustrated). In response to the depressionof button 120 display controller 164, in step 368, causes motor driver142 to apply energization signals to the base unit 54 to cause the motorto turn in the directions in which the lower brush should be turned.Initially, the spindle teeth may not be seated in the brush notches 264.However, owing to the alignment of the brush with the spindle, afterless than 90° rotation of the spindle and the biasing force provided byspring 118, spindle teeth 112 seat in the brush head notches 264. Oncethe spindle teeth 112 are so seated, the continued rotation of thespindle 104 results in a like rotation of cleaning head lower brush 58.

As discussed above, once the cleaning head shells 192 and 194 areclamped together, the harvested bone is pressed between the bristles 268and 290 of, respectively, the lower brush 58 and upper brush 59. Therotation of the lower brush bristles, forces the bone to rub againstboth sets of bristles 268 and 290. The rubbing of the bone against thebristles strips ligaments and other debris off the bone so as to cleanthe bone, step 370. It is believed that once actuated, cleaning head 56of this invention can clean bone stock in 5 minutes or less and, in somecircumstances, 3 minutes or less.

It should be understood that during steps 368 and 370, the motor isactuated according the sequence data specified in direction field 278 inthe memory 272. Likewise, unless modified by the user, the motor is runat a speed necessary to rotate the brush according to the data specifiedin default speed field 276.

At the conclusion of the cleaning process, cleaning head 56 is removedfrom the base unit 52. The cleaning head shells 192 and 194 are unlockedfrom each other so as to allow removal the cleaned bone from the head56. Both these process are called out as step 372 in FIG. 19B.

Mill head 60 is then coupled to the base unit 52, step 373. To soposition the mill head 60, the mill head bottom shell is seated on thepedestal surface 76 so that pedestal teeth 84 seat in bottom shellnotches 312 and catch tray 310 seats in pedestal notch 83. Mill head 60is releasably secured to the base unit 52 by the seating of theretaining arms 86 so that the arm fingers 88 seat in the top shellnotches 328. During this process, the spindle alignment pin 110 seats inthe mill element opening 332. This serves to alignment the mill element62 with the drive spindle 104 so that the element openings 334 are on acircle disposed over the spindle teeth 112. The seating of base unitteeth 84 in mill head notches 312 prevents rotation of the mill head 60relative to the base unit 52.

As mentioned above, as long as the display controller 164 recognizesthat the base unit 52 is attached to the control console 66, the displaycontroller 164, through RFID interface 168 continues to performinterrogations to determine whether or not a device is attached to thebase unit. Once the mill head 60 is fitted to the base unit 52, inresponse to this basic interrogation, the mill head RFID 320, writes outdata indicating that the mill head is attached to the base unit. Inresponse to this event occurring, the display controller 164, in step374, reads out all the data in the mill head RFID 320.

Based on the data read from the mill head RFID, in a step 376, displaycontroller 164 configures system 50 to actuate the mill head 60. Thisprocess involves generating instructions to operate the base unit motor54 at the speed which will cause the mill element 64 to rotate at theappropriate speed. Also, the display controller 164 causes data to bepresented on the console display 174 to indicate that a mill head 60 isattached to the base unit 52.

The cleaned bone stock is placed in the feed sleeve 306 and the plunger307 placed in the sleeve over the bone, step 378. Surgical personnelstart the actual milling process by depressing the base unit button 120.The personnel also press downwardly on the plunger 307 so as to pressthe bone stock against the mill element 62. These two steps are calledout as step 380 in FIG. 19C.

As a consequence of the display controller 164 detecting the depressionof button 120, (step not identified) in step 380 the display controller164, in step 380, sends instructions to the motor driver 162 that causesthe driver to actuate the base unit motor 54 at the speed necessary torotate the mill element 62 at the desired speed. Again, it should beunderstood that based on the data in memory 320 this speed may bedifferent than the speed at which the motor 54 is actuated to activatethe cleaning head 56. As a consequence of the bone being pressed againstthe mill element 62 and the mill element rotating so that the cuttingedges 340 turn towards the impingement plate 308, the bone is compressedbetween the mill element scallops and the impingement plate. The millelement cutting edges 340 shear the bone stock into chips. The chipsfall into the catch tray 310.

After the milling process, the catch tray 310 filled with bone chips isremoved from the mill head, step 384. The chips are then extracted forfurther processing and subsequent implantation into the patient.

System 50 eliminates the need to hand clean bone stock before it isground into chips. Thus, the possibility that the individual chargedwith cleaning the bone stock, will, in the cleaning process, rip a gloveso as to result in the risk of cross contamination is likewiseeliminated.

Still another feature of this invention is that the most costlynon-disposable components used to perform the cleaning process, the baseunit 52 and the control console 66, have two functions. These componentsare used to activate both the mill element 62 in the mill head 60 andthe brush 58 in the cleaning head 56. This reduces the costs ofproviding system 50 of this invention.

The memories (RFIDs) 270 and 320 provide configuration data about,respectively, the brush 58 and mill element 62, with which they areassociated. Control console 66, based on these configuration data,controls actuation of the base unit motor 54 so that the motor operatesat the speed for the attached brush 58 or mill element 62. Thisminimizes the amount of time personnel need to configure the system 50for operation when first the cleaning head and then the mill head aremounted to the base unit. Given that the data transfer from the cleaninghead and the mill head is automatic, the likelihood the human errorcould result in the console receiving incorrectconfiguration/operational data is essentially eliminated. Thus, thecontrol console 66 ensures that the base unit motor 54 operates at theappropriate speed regardless of which head, the cleaning head 56 or themill head 60, is attached to the base unit 52.

Still another feature of system 50 of this invention is that, in someversions of the invention, the only disposable portions of the cleaninghead 56 are the brushes 58 and 59. This further reduces the costsassociated with operating system 50.

VI. First Alternative Cleaning Head

FIG. 20 illustrates the basic features of an alternative cleaning head410 for use with system 50 of this invention. Head 410 includes lowerand upper shells 412 and 414, respectively. A lower brush 416 isdisposed in the lower shell 412. An upper brush 418 is disposed in theupper shell 414. A drive assembly, the components of which are discussedbelow, connects the brushes for simultaneous rotation. In one version ofthe invention, the brushes are connected together so that when the lowerbrush 416 rotates in one direction, the upper brush 418 rotates in theopposite direction.

Lower shell 412 is formed from the same material from which lower shell192 of cleaning head 56 is formed. The lower shell 412, seen best inFIG. 24, has the same basic circular shape as shell 192. Moreparticularly, at the disk shaped base of the shell there is a centerlocated opening (not illustrated) through which the base unit drivespindle 104 can extend. There are notches 422 in which the pedestalteeth 84 seat when cleaning head 410 is seated on the base unit 56.Lower shell 412 has a circular ring 424 that extends upwardly from thebase. Ring 424 of shell 412 is shorter in height than ring 214 of shell194. Accordingly the notches 426 formed in the ring in which the baseunit retention arms 88 seat extend downwardly from the exposed outwardlydirected face of the ring 426. Slots 224 are formed in the outwardlydirected face of ring 424 for the same reason the slots 224 are presentin shell 192.

Cleaning head upper shell 414 is formed from the same material fromwhich the lower shell 412 is formed. Upper shell 414, like shell 194 ofcleaning head 56, is cylindrically shaped. As seen best in FIGS. 20 and21, upper shell 414 is larger in top-to-bottom height than shell 194. Anumber of coaxial bores extend longitudinally through upper shell 414. Abore 430 extends upwardly from the bottom of upper shell 414. Bore 430extends approximately 50% of the distance through the shell 414 and isthe largest diameter bore. A bore 432 is located immediately above andis contiguous with bore 430. Bore 432 has a diameter that is slightlyless than that of bore 430. Upper shell 414 is shaped so that the outerperimeter of bore 432 is defined by a circular ring of teeth 434 thatextends inwardly from an interior surface of shell 414.

Above bore 432 there is a bore 436, a bore 438 and a bore 440. Bore 436is present for manufacturing reasons and has a diameter between that ofbore 430 and bore 432. Bore 438 is immediately above bore 436. Bore 438has a diameter less than that of bore 436. Bore 440 extends between bore438 and the top face of shell 414. Bore 440 has a diameter less thanthat of bore 438.

The same pins 248 that extend downwardly from the base of upper shell194 extend downwardly from the base of upper shell 414.

Lower brush 416 has a substrate 444 similar to substrate 260. As seen inFIG. 23, a bore 446 extends through substrate 444 along the axis aroundwhich substrate 444 rotates. Bore 446 has a square cross-sectionalshape. The width across bore 446 is equal to or greater than the maximumouter diameter of the drive spindle alignment pin 110. The notches 264present in substrate 260 are equiangularly spaced around the bore 446 ofsubstrate 444.

Substrate 444 is further shown as having a closed end notch 448 on theunderside of the substrate. This is to indicate that substrate 444, likesubstrate 260, holds the memory (RFID) 270 (FIG. 5) in which dataregarding the identity and operation of the cleaning head 410 arestored.

Bristles 268 extend upwardly from the top directed face of substrate444. Not identified is the adhesive layer between the substrate 444 andthe bristles.

Upper brush 418 has a disc shaped superstrate 450 with an outer diameterat least 0.5 mm smaller than the diameter of shell bore 430. Superstrate450 is formed with three bores. A through bore 452 extends axiallythrough the substrate along the longitudinal axis of the substrate.There are also two closed end bores 454 and 456. Bores 452, 454 and 456are linearly aligned. Bore 456 is located immediately inward of theouter perimeter of superstrate 450.

The drive assembly of cleaning head 410 includes a shaft 460, nowdescribed by reference to FIGS. 24 and 25. Shaft 460 is formed fromstainless steel or other metal or, in some cases, as plastic and as asingle piece unit. The shaft 460 is shaped to have a generally elongatedcylindrical body 462. Body 462 has a diameter that is less than thediameter of bore 452 of upper brush substrate 450. Formed integrallywith the body 462, at the bottom end of the body, shaft 460 has a foot464. Foot 464 has a rectangular cross-sectional profile. Moreparticularly, shaft foot 464 is shaped to closely fit in bore 446internal to lower brush substrate 444. While not illustrated, shaft foot464 may have a bore that extends upwardly from the base of the foot.This bore is shaped to receive the alignment pin 110 integral with thebase unit drive spindle 104. Shaft 460 is further formed to have anelongated slot 466. Slot 466 is located in shaft body 462 approximately2 to 4 cm below the top of the shaft. Slot 464 extends diametricallythrough the shaft body 462.

Shaft 460 is positioned so that foot 464 is seated in lower brushsubstrate bore 446. The shaft body 462 extends through and above bore452 in the upper brush substrate 450. As seen in FIG. 21, shaft body 462also extends through upper shell bores 436, 438 and 440.

The cleaning head drive assembly also includes three gears 468, 470, 472located immediately above the top of the upper brush substrate 450 asseen best in FIGS. 20 and 24. Gear 468 is slip fitted over the sectionof the shaft body 462 that extends above the superstrate 450. A ringshaped collar 474 integral with gear 468 extends upwardly from the gearso as to also extend around the shaft body 462. Collar 474 is formed tohave diametrically opposed openings 476, one shown. A pin 478 extendsthrough collar openings 476 and shaft slot 466 to couple gear 468 to theshaft 460 so that the gear rotates with the shaft. Given that pin 478extends through shaft slot 466 it should be apparent the gear 468, likeupper brush 418, is able to move longitudinally along shaft 462.

It should further be appreciated that when cleaning head 410 isassembled, collar 474 may extend into upper shell bore 438. Accordingly,the upper shell 414 is formed so that bore 438 is of larger diameterthan collar 474.

Gears 470 and 472 are both rotationally mounted to the top surface ofsuperstrate 450. More particularly, gear 470 is disposed over the shaftof an arbor 480 seated in superstrate bore 454. Gear 472 is disposedover the shaft of an arbor 482 seated in superstrate bore 456. Pins 486hold the gears 470 and 472 to, respectively, arbors 480 and 482. Awasher 484 is disposed between each gear 470 and 472 and the overlyingpin head. Gear 470 interlocks with both gears 468 and 472. Gear 472 ispositioned so the teeth of the gear project beyond the perimeter ofsuperstrate 450.

Bristles 290 extend downwardly from superstrate 450. Not identified isthe adhesive layer that holds the bristles 290 to the superstrate.

Cleaning head 410 also includes a ring 488. Ring 488 is dimensioned toslip fit over the shaft body 462. For reasons apparent below, thisversion of the invention may include a number of different rings ofdifferent heights.

Bone stock is cleaned using cleaning head 410 by first placing the lowerbrush 416 in lower shell 412. Shaft 460 is mounted to the brush 416 sothe shaft foot 464 seats in substrate bore 446. A ring 488 having aheight slightly less than the height of the bone stock is slipped overthe shaft body 462. The bone is placed on the brush bristles 268.

Upper brush 418 is disposed over the lower brush so the shaft bodyextends through superstrate bore 452. It should be appreciated that thepresence of ring 488 limits the extent to which the upper brush 418 ispushed down against the bone stock.

The upper shell 414 is then disposed over the lower shell 412, the bonestock and the brushes 416 and 418. As a consequence of the positioningof the upper shell 414 in place, the teeth of the gear 472 that extendbeyond upper brush substrate 450 engage the teeth 434 internal to theupper shell 414.

Cleaning head 410 is then releasably coupled to the base unit pedestal74 in the same manner in which cleaning head 56 is so attached. Thecleaning head 410 is actuated in the same general process in whichcleaning head 56 is actuated. If the cleaning head, more particularly,the lower brush 416 is provided with a memory 270, in which datadefining the operational parameters of the cleaning head are stored,control console 66 activates the base unit motor 54 based on these data.

During the actuation of the cleaning head 410, base unit spindle 110rotates the lower brush 416. This results in a like rotation of shaft460. The rotation of shaft 460 results in the rotation of gears 468, 470and 472. The engagement of the teeth of gear 472 in upper shell teeth434 results in the rotation of upper brush 418 around the shaft 460.More particularly, superstrate 450 and the upper brush are rotated in adirection opposite that in which the lower brush 416 rotates. Thus,bristles 268 and 290 simultaneously rub against opposed surfaces of thebone stock in opposed directions. This simultaneous brushing of twosurfaces of the bone stock in opposed directions rolls the bone stockbetween the brushes during the cleaning process. This facilitates thethorough cleaning of the bone stock and potentially reduces the overalltime required to clean the bone stock.

VII. Integrated Cleaning and Mill Head

In another alternative version of this invention, the system may includea single head 490 now described by reference to FIG. 26, with componentsfor both cleaning and milling bone stock. Head 490 includes lower andupper plates 492 and 496, respectively. Rotatably disposed between theplates 492 and 496 is a mill element 494. A cleaning module, includinglower and upper shells 502 and 508, respectively is moveably mounted toupper plate 496. Lower and upper brushes 504 and 506, respectively, aredisposed inside the brush housing. Lower brush 504 is provided withfeatures that releaseably couple the brush to the mill element 494 sothat the brush rotates in unison with the mill element.

The head lower plate 492, is formed from a plastic such as asterilizable plastic such as a polycarbonate plastic. As seen in FIG.27, the lower plate is formed to have cylindrical base 510. Base 510 hasa diameter that allows it to seat on the base unit pedestal top surface76 within lip 78. Base 510 has a height that is at least as great asthat of lip 78 above surface 76. Lower plate 492 is further formed tohave a rim 512 that is integral with and extends circumferentially andradially beyond base 510. The base is formed so as to have four notches514 and two notches 516 (one notch 514 seen in FIG. 27). Notches 514 arelocated around the bottom surface of base 510. Notches 514 aredimensioned to receive teeth 84 when head 490 is seated on base unit 52.Notches 516 are diametrically opposed to each other. Notches 516 arelocated at the top of base 510 immediately below when the rim 512projects outwardly from the base. The notches 516 are positioned anddimensioned to receive the retention arms fingers 88 to facilitate thereleasable coupling of the head 490 to the base unit 52.

Lower plate 492 is further formed so as to have a circular void space518 concentric with and located within rim 512. More specifically thelower plate 492 is formed so that the void space 518 extends through rim512 and partially through the base 510. A circular opening 520 seen inphantom in FIG. 27, extends concentrically from the bottom of void space518 through the plate base 510. Opening 520 has a diameter slightlygreater than that of the drive spindle head 108. The lower plate is alsoformed with a discharge port 522. Discharge port 522 is square in crosssection and extends from the bottom of the void space through the platebase 510. Port 522 is located between opening 520 and the outerperimeter of plate base 510.

While not seen in the Figures, it should be understood that a catch traysimilar to catch tray 310 is removably mounted to the lower plate base510. Also not illustrated are the rails integral with the lower plate492 that facilitate the removable mounting of the catch tray belowdischarge port 522.

Upper plate 494 is formed from the same type of plastic from which lowerplate 492 is formed and is generally disc-shaped. The upper plate 494has an outer diameter equal to the outer diameter of base plate rim 512.The upper plate 494 is formed to have a center located hole 524 (shownin phantom in FIG. 28). Upper plate 496 is further formed to have a feedport 526. Feed port 526 is generally square in shape. In the illustratedversion of the invention the plate is shaped so that the interiorsurfaces of the plate 496 that lead into the port are inwardly taperedsuch that the size of the port 526 decreases progressing inwardly fromthe top of the plate. When head 490 is assembled, the plates 492 and 496are oriented so that the upper plate feed port 526 is in registrationwith the lower plate discharge port 522.

The upper plate 496 is further formed to have a center locatedtube-shaped sleeve 528. The plate is formed so that sleeve 528 extendsaround and above plate center located-hole 520.

An impingement plate 530, seen as a phantom rectangle in FIG. 28, ismounted to the bottom of the upper plate 496. The impingement plate 530is located immediately adjacent the plate feed port 526.

Two parallel webs 534 extend upwardly from upper plate 496. In someversions of the invention, webs 534 are formed integrally with the upperplate 496. The webs 534 are positioned so that the plate hole 524, feedport 526 and sleeve 528 are located between the webs. Webs 534 arespaced apart from each other a distance greater than the outer diameterof shells 502 and 508. In the illustrated version of the invention, arectangular rib 536 is formed integrally with each web 534. Each rib 536(one shown) extends outwardly from the face of the web that is directedtoward sleeve 528. Ribs 536 provide structural strength to the webs 534.

Webs 534 are generally solid structural members. Each web 534 is furtherformed to have a slot 540 immediately below the top of the web thatextends across the web. The slots 540, which are in registration witheach other, are each formed to have three downwardly directedindentations 542, 544 and 546. Two indentations, indentations 542 and546, are located at the opposed ends of each slot. Each indentation 544extends downwardly from the mid-point of the slot 540 with which it isintegral.

Mill element 494 includes a cutting disc 540. Disc 540 has the samebasic features of mill element 62. Disc 540 has an outer diameterslightly less than the diameter of the lower plate void space 518. Millelement 494 also has a post 544 that extends upwardly from the topsurface of disc 540, the surface above which the disc scallops (notidentified) extend. In the illustrated version of the invention, post544 extends upwardly from a circular base 542 welded or otherwisesecured to the top of disc 540. Post 544 has a diameter less than thatof the underlying base 542.

A circular head 546 is mounted to the top of post 544. Head 546 isshaped to have an alignment pin 548 similar to spindle alignment pin110. The head 546 also has teeth 550 similar in drive teeth 112 integralwith drive spindle 112. Teeth 550 are disposed equiangularly around andare smaller in height than pin 548. Mill element 494 is dimensioned sothat when head 490 is assembled, the cutting disc 540 is disposed in thelower plate void space 518, post 544 extends through sleeve 528 andelement head 546 is spaced above the sleeve.

Lower shell 502 has the same basic shape of shell 192 of cleaning head56. Shell 502 does not have notches that facilitate the seating of theshell or the coupling of the shell to the base unit 52. Shell 502 has anotch 554 that extends downwardly from the outer lip of the shell. Insome versions of the invention, notch 554 extends to the base of theshell 502. Lower shell 502 is further formed to have two diametricallyopposed, linearly aligned closed end bores 556.

Pins 558 moveably mount the lower shell 502 to webs 534 integral withupper plate 494. Each pin 558 has an end that is seated in one of theshell bores 556. The end of the pin 558 that extends outwardly of theshell 502 extends into the adjacent web slot 540. Pins 558 aredimensioned relative to the slots 540 so that the pins can slidably movein the slots and indentations 542-546. It should therefore beappreciated that the pins 558 allow the lower shell 502, and thecomponents mounted to the shell, to both move over the upper plate 496and to pivot.

Upper shell 508 has the same basic cylindrical shape as shell 194 ofcleaning head 56. A rectangularly shaped notch 560 extends through thedownwardly extend skirt of the shell 194 (skirt not identified).Collectively, shells 502 and 508 are shaped so that, when assembledtogether to form the cleaning module housing, upper shell notch 560 isin registration with lower shell notch 554. It should also be understoodthat notches 554 and 560 share a common width. Two linearly alignedlaterally extending bores 564 are also formed in upper shell 508. Bores564 are positioned to open into notch 560.

Pins 248 (one shown) integral with upper shell 508 seat in slots 224formed in the lower shell 502 to facilitate the releasable coupling ofthe shells together. Again, collectively, shells 502 and 508 form thehousing of the cleaning module of head 490.

Lower brush 504 has the same basic features of brush 58. Upper brush 506has the same basic features of brush 59.

Head 490 of this version of the invention also includes a slide plate568. Plate 568 is mounted in contiguous notches 554 and 560 integralwith the cleaning module housing. Plate 568 has a generally rectangularshape. The width of the plate 568 is selected to facilitate the slidingmovement of the plate 568 in the notches 554 and 560. The opposed sidesurfaces of the plate 568 are each formed to have longitudinallyextending groove 570 (one shown). A tab 572 extends perpendicularly awayfrom the plate 568. In the illustrated version of the invention, theplate 568 is constructed so that when the head 490 is assembled, tab 572extends over the top of the upper shell 508.

Two pins 574 hold the plate 568 to the cleaning module housing. Moreparticularly, each pin 574 is partially seated in one of the bores 564formed in the upper shell 508. The exposed end of the pin 574 seats inthe adjacent groove 570 integral with the plate 568. Pins 574 thus holdthe plate to the cleaning module housing while allowing the plate toslide so as to selectively cover and expose notches 554 and 560.

While not illustrated, a memory similar to memory 320 may be disposed inthe lower plate base 510. This memory includes data indicating thespeeds at which both the mill element 494 and lower brush 504 should berotated.

To use head 490, the head is initially mounted on the base unit 52. As aconsequence of the seating of the lower plate base 510 on base unitpedestal surface 76, the drive spindle alignment pin 110 causes millelement 494 to align with the drive spindle 104.

To load bone stock for cleaning in the cleaning module, the module isfirst moved so that pins 558 seat in web slot indentations 546. Thecleaning module is thus positioned so it is spaced furthest away fromthe upper plate feed port 526. The cleaning module is then pivoted sonotches 554 and 560 and plate 568 are upwardly directed. Plate 568 isopened to expose notches 554 and 560. The bone stock is passed throughthe notches, between the brushes 504 and 506. To ensure sufficientclearance between the notches, the person perform this process may pullon the post integral with brush 506 to hold it away from brush 504.Plate 568 is returned to the closed state.

The cleaning module is then moved so that pins 554 seat in web slotindentations 544. As a consequence of the cleaning module being sopositioned, the alignment pin 548 integral with mill element 494 in thecomplementary opening formed in brush 504 aligns the drive openingsinternal to the brush with the circle in which teeth 550 are disposed.Collectively, the components of head 490 may further be constructed sothat when pins 558 seat in indentations 544, the undersurface of lowershell 502 seats against sleeve 528.

The memory integral with head 490 contains data that informs the controlconsole display controller 164 that the head is a combined cleaning andmill head, step 582 of FIG. 29A. In response to this information,display controller 164 presents on display 174 buttons requesting theuser to indicate if the device is to be operated in the cleaning mode orthe milling mode, step 584. Upon entry of a command, step 585, that thedevice is to be operating in the cleaning mode, display controller, instep 586, prepares the instructions to cause the motor driver 162 toactuate the motor 54 in a manner appropriate to rotate brush 504 at theappropriate speed and in the appropriate direction. Once button 120 isdepressed, (step not shown) control console 66 actuates the motor 54 soas to cause the appropriate actuation of the cleaning module, step 588.

In step 588 the actuation of the motor 54 and drive spindle 108 resultin a like actuation of the mill element 494. The cutting disc 540, post544 and head 546 are all rotated. If teeth 550 are not already seated inthe brush openings, identical to openings 264 of FIG. 12, they seat inthese openings during the initial rotation of the head 546. As aconsequence of the engagement of teeth 550 in the brush openings, thebrush undergoes a like rotation. As with the rotation of brush 58, thisaction results in the cleaning of the bone stock.

Once the cleaning processes is terminated, the control console mayreturn to step 584 to await an indication if, the next time the motor isactuated, it is actuated to actuate the mill element 494 or the brush504

Once the bone is cleaned, the cleaning module is moved so that pins 554seat in web slot indentations 542, the indentations adjacent feed port526. The cleaning module is pivoted so that the module notches 554 and560 face the feed port 526. Plate 568 is slide to the open state.Gravity causes the cleaned bone stock to fall into the feed port 526. Tofacilitate this process, it may be necessary to pull on the postintegral with brush 506 so as to hold the brushes apart.

Once the bone stock is transferred to the lower plate, essentially themill assembly, the cleaning module is moved away from the feed port 526.This provides clearance for the subsequent insertion of a plunger intothe feed port.

The user depresses the appropriate button presented on the controlconsole display 174 to indicate that head 490 is now to be operated inthe cleaning mode, step 585 is reexecuted. In response to this buttonbeing depressed, in step 562, the display controller 164 readies theinstructions to cause the base unit motor 54 to be actuated at a speedappropriate for rotating the cutting disc 540, step 562.

When the bone is to be milled the button 120 is depressed, (step notillustrated). This results in the control console 66 actuating the baseunit motor 54 at the appropriate speed, step 564. Simultaneously withthe actuation of the motor a plunger, such as the plunger 307 of FIG.16, is used to force the bone stock against the rotating cutting disc540. The rotating cutting disc 540 and impingement plate 530 cooperateto convert the bone stock into bone chips.

One advantage of head 490 of this invention is that a single unitincludes the components that first clean the bone stock and then millthe stock into chips. The need to change heads between these processesis eliminated. A further advantage of a system of this inventionincluding head 490 is that the transfer of the cleaned bone from thecleaning module to the mill module occurs using gravity. The need tohave an individual perform this transfer is eliminated.

It should of course be appreciated that there may procedures in which itmay be appropriate to use one of the cleaning module or the millingmodule of this invention but not both the modules of head 490.

VIII. Alternative Brush

FIGS. 30 and 31 illustrate an alternative brush 602 that can be employedwith the system of this invention. The illustrated brush 602 is a lowerbrush. Versions of the brush can be configured as an upper brush. Brush602 includes a disc substrate 606. A number of brush heads 608 (oneshown) are removably attached to the substrate 606.

Substrate 606 is dimensioned to fit in and rotate in the head/module inwhich the brush 602 is seated. Not shown is the opening on the undersideof the substrate for receiving the alignment pin 110 or 548. Also notshown are the openings in the underside of substrate 606 for receivingthe drive teeth 112 or 550. Substrate 606 is formed to have fourequiangularly spaced apart slots 610. Each slot 610 starts from alocation radially spaced from the center of the substrate and extendsradially outwardly to the outer perimeter of the substrate. While notidentified, it can be seen in the Figures that each slot 610 includes awide width lower section and an upper section with narrower width. Theslot lower section, it is observed, form the closed end base of the slot610. Slot 610 upper section is open to the surface of substrate 606.

Each brush head 608 includes a rectangular base 614. Base 614 has awidth that allows the base to slide in the lower section of substrateslot 610. Bristles 616 extend upwardly from the top surface of base 614.Bristles 616 may be adhesively secured to the base 614. Alternatively,the bristles may be compression packed in closed end bores (notillustrated) in the base. Regardless of how the bristles 616 are mountedto the base 614, the bristles are extend across the base a distanceapproximately equal to that of the width of the upper section of slot610. Bristles 616 are of sufficient length that the bristles extendabove and out of the upper section of slot 610.

Brush 602 of this invention is prepared for use by sliding a brush head608 in each one of the substrate slots 610. Brush 602 is then mountedthe cleaning head/module and used in the same manner as the previouslydescribed brushes 58, 59, 416, 418, 504 or 506.

Once a system of this invention in which one or more brushes 602 isemployed, the brush heads 608 can be removed from the substrate (orsuperstrate) for cleaning or disposal and replacement. The substrate (orsuperstrate) can be independently sterilized. Thus use of brushes 602 ofthis version of the system of the invention thus eliminate the need to,after each use, discard the whole of the brush.

IX. Second Alternative Cleaning Head

A second alternative cleaning head 630 of this invention is nowdescribed by initial reference to FIG. 32. Cleaning head 630 includes abase 632. Base 632 is dimensioned to be seated over the base unit topsurface 76. Brush 58 (or brush 602) is rotatably disposed within thebase 632. A flexible cap 634 is fitted to the base 632 so as to extendover the brush 58.

Cleaning head base 632 can be formed from the same material from whichthe shells 192 and 194 of head 56 are formed. Alternatively, if cleaninghead 630 is a use-once unit, base 632 may be formed from a sterilizableplastic such as a polycarbonate plastic. As best seen in FIGS. 33 and34, base 632 is formed to have a cylindrical foot 638 dimensioned toseat on base unit surface 76. Foot 638 has an outer diameter that allowsthe foot to be slip fitted within the circular void space defined by thebase unit lip 78. Four equiangularly spaced notches 640 extend upwardlyfrom the bottom of the foot 638 around the outer perimeter of the foot.Notches receive pedestal teeth 84 when the cleaning head 630 is seatedon the base unit 52. In the illustrated version of the invention, agroove 642 extends inwardly around the circumferential outer surface ofthe foot 638. Foot 638 is further formed to have two diametricallyopposed notches 644 (one shown in FIG. 32) that extend inwardly from theouter circumferential surface of the foot. Notches 644 intersect groove642. Each notch 644 is dimensioned to receive a separate one fingers 88integral with the base unit retention arms 86. Base foot 638 also has athrough hole 646 that extends top-to-bottom through the foot. Hole 646is centered along the top to bottom longitudinal axis of the foot 638.Hole 646 is dimensioned to allow the base unit spindle head 108 freelymove therein.

While not illustrated, it should be understood that RFID 270 and coil271 (FIG. 5) are embedded in the foot 638 of cleaning head base 632. Thedata in RFID 270 are used by control console 66 to regulate theoperation of the system base unit 52 when cleaning head 630 is attached.

Base 632 is further formed to have a multi-section ring 647 that extendsupwardly from the outer perimeter of foot 638. The ring has a lowersection, section 650, with a relatively thick cross sectional width. Thering has an upper section, section 652, with a narrower cross sectionalwidth. Ring 647 is shaped so that the inner walls of the lower and uppersections 650 and 652, respectively, form a shell that defines a voidspace 654 above foot 638 of constant diameter. Void space 654 has adiameter that is at least 0.5 mm greater than that of brush 58. Thus,around the outer surface of the ring the ring upper section 652 isstepped inwardly from the lower section 650. The ring is of sufficientheight so that void space 654 is able to receive all of the brush; boththe substrate 260 and the bristles 268. The ring is further formed tohave a flange 656 that projects radially outwardly from the top of theupper section 652. While not called out, it can be seen in FIG. 34 thatthe outer surface of the flange is outwardly tapered.

Cleaning head base 632 is further formed to have a lip 660 that extendssubstantially circumferentially around and above the ring. Lip 660 isformed to have a horizontal section 662 that extends radially away fromthe top of the ring lower section 650. Lip 660 also has a verticalsection 664 integral with the outer end of the horizontal section 662.More particularly, the lip 660 is formed so that vertical section 664extends both outwardly and upwardly away from the horizontal section. Inmany versions of the invention, including the illustrated version, lip660 is formed so that the top edge of the vertical section 664 islocated above the top of the ring upper section 652.

The cleaning head base 632 is further formed to have a spout 668. Thespout 668 includes a finger 670 that extends radially and upwardly froman arcuate section of the ring lower section 650. The face of thisfinger 670 is flush with the adjacent arcuate step between the ringupper and lower sections 652 and 650, respectively. Finger 670 is formedwith a tip 672 that extends radially outwardly beyond the portion of thefinger on either side of the tip. Spout 668 also has a three-wall chute678 that extends radially beyond finger 672. The walls that form thechute 678, two opposed side walls as well as a wall between the sidewalls are extensions of the lip vertical section 664 that are extendvertically upwardly more than the vertical section itself. Collectively,the outer end of the spout finger 670 and the adjacent though spacedaway chute walls defining an opening 676 through the spout 668. In theillustrated version of the invention a three-sided lip 680 extendsinwardly from the inner faces of the chute walls into the opening 676.Opening 676 is dimensioned to allow the seating thereon of mill headfeed sleeve 306.

While not identified, it is observed from FIG. 32 that the upwardlydirected portion of the cap lip 660 that leads to spout 668 is recessedrelative to the adjacent surface of the lip 660.

The cap 634 of cleaning head 630 is formed from a flexible material suchas a thermoplastic resin. The cap 634, shown best in FIGS. 32, 35 and 36has a ring shaped rim 684. A concavo-convex dome 686 extends inwardlyfrom the inner edge of the rim 684 and forms the center of the cap 634.The cap 634 is shaped so that the dome 686 extends upwardly away fromthe outer surface of rim, away from the outer surface of the underlyingbrush 58. Bristles 688, also part of cap 634, extend downwardly from thesurface of the dome 686 directed towards brush 58.

A C-shaped lip 690 extends outwardly from the outer perimeter of the caprim 684. One end of the lip 690 is contiguous with the outer edge of therim 684. The cap 634 is shaped so that the lip 690 curves under the sideof the rim that faces base 632. The cap 634 is formed so that the lip690 can snap fit over flange 656 integral with base 632. Cap 634 isfurther formed to have a number of flexible tabs 692. Tabs 692 projectradially and upwardly away from the outer surface of the cap lip 690adjacent where the lip starts to curve under the rim 684. Tabs 692 serveas finger holds for stretching the cap over and removing the cap fromthe base ring upper section 652.

Cleaning head 630 of this invention is used by seating the brush 58 (orbrush 602) in the base void space 654. The bone stock to be cleaned andmilled is placed on brush bristles 268. Cap 634 is snap fitted over thebase ring upper section 652. The cleaning head 630 is then fitted andsecured to the base unit 52.

The base unit motor 54 is actuated as previously described in order toactuate the brush 58. During the time the brush 58 is rotated, theindividual responsible for the cleaning process may press down on thecap dome 686. This action presses the caps bristles 688 against thebone. The bone is therefore compressed between both the brush bristles268 and the cap bristles 688. The rotation of the brush 58 rotates thebone stock against both sets of bristles 268 and 688 to result in thestriping of ligaments and other debris away from the bone.

Once the bone is cleaned, the cleaning head 630, possibly with cap 634still attached, is removed from the base unit 52. Mill head 60 isattached to the base unit 52. As seen in FIG. 37, the cleaning head 630is then positioned so that chute 678 extends on the top of the mill headfeed sleeve 306. The underside of lip 680 that surrounds spout opening676 abuts the top edge surfaces of the feed sleeve 306. Thislip-to-sleeve contact prevents from the cleaning head 630 from slidingdown the mill head feed sleeve 306

The cleaning cap 634 is removed from the rest of the head 630. Thepresence of lip 660, which flares outwardly, prevents the cleaned bonestock from falling out of the base 632. Assume the bone stock passesinspection, a hand held instrument, such as forceps, are used to guidethe cleaned bone stock off the brush 58 through the spout 668 and intothe feed sleeve 306. During this process, both lip 660 and the walls ofchute 678 prevent the bone stock from falling out of the cleaning headbase 632.

In the described version of the invention, once the bone is transferredinto the feed sleeve 306, plunger 307 can then be fitted into the feedsleeve without first having to remove cleaning head 630.

Cleaning head 630 and mill head 60 of this embodiment of the system ofthis invention do more than, respectively, clean and mill the bonestock. These components are designed to be coupled to each between thecleaning and milling processes. In the described version of theinvention this mating occurs without having to provide supplementalcomponents such as a set screws or ball pins with moving components.This component mating minimizes the extent the cleaned bone stock needsto be handled before it is transferred to the mill head 60. Thissimplifies the transfer of the bone stock to the mill head and reducesthe likelihood that, during the transfer process, the bone stock will beinadvertently mishandled.

Lip 660 and chute 668 of cleaning head 630 do more than function asstructural members that prevent the bone stock from inadvertently fallout of the head base 632. The lip 660 and chute 668 function as featuresof the base 632 an individual can hold when handling the base. Thesefeatures are both spaced away from the brush 58. Thus, an individual byholding onto either the base lip 660 or chute 668 can handle the basewhile having his/her fingers spaced from the brush 58. This reduces thelikelihood that the individual may inadvertently touch the brush 58 andthe possible problems caused by such contact.

X. Third Alternative Cleaning Head

Referring to FIGS. 38-47, a third alternative cleaning head 700 isshown. The cleaning head 700 comprises a base 702. A shell 704 ismounted to the base 702. The shell 704 defines a void space 706 forreceiving the bone to be cleaned. A cap 707, (shown only in FIG. 39,) isremovably mounted on top of the shell 704 to enclose the void space 706.The base 702, shell 704, and cap 707 can be formed from the samematerial from which the shells 192 and 194 of head 56 are formed.Alternatively, if cleaning head 700 is a use-once unit, base 702, shell704, and cap 707 may be formed from a sterilizable plastic such as apolycarbonate plastic.

The base 702 is shown in FIGS. 38 and 39 as being rectangular in shapewithout any features for engaging the base unit 52. Accordingly, thecleaning head 700 may be a stand-alone unit for cleaning bone in whichthe base 702 is simply attached to a separate drive system (shown butnot numbered). However, in other embodiments the base 702 has an outerdiameter that allows the base 702 to be slip fitted within the circularvoid space defined by the base unit lip 78. As a result, the cleaninghead 700 can be operated by the base unit 52. In this case, like thesecond alternative cleaning head 630, the base 702 is circular in shape(not shown) and four equiangularly spaced notches (not shown) extendupwardly from the bottom of the base 702 around the outer perimeter ofthe base 702. The notches receive the pedestal teeth 84 when thecleaning head 700 is seated on the base unit 52. A groove (not shown),like groove 642, extends inwardly around the circumferential outersurface of the base 702. Base 702 has two diametrically opposed notches(not shown), like notches 644 (one shown in FIG. 32) that extendinwardly from the outer circumferential surface of the base 702. Eachnotch being dimensioned to receive a separate one of the fingers 88integral with the base unit retention arms 86.

Referring back to the embodiment of FIG. 38, the base 702 has a throughhole 708 that extends top-to-bottom through the base 702. The hole 708is centered along the top to bottom longitudinal axis of the base 702.The hole 708 is occupied by a spindle 710. The spindle 710 forms part ofa drive assembly 714 of the cleaning head 700. The spindle 710 isrotatably supported by bearings 712 mounted to the base 702. A needlebearing assembly, shown in exploded view, is disposed between base 702and the overlying surface of the spindle 710. The needle bearingassembly absorbs the thrust load of the spindle and the attachedcomponents. In alternative embodiments in which the cleaning head 700 isoperated by the base unit 52, the spindle 710 is not present and thehole 708 is dimensioned to allow the base unit spindle head 108 tofreely move therein and engage the cleaning head 700.

Referring to FIGS. 38 and 39, the shell 704 includes a shell base 716 towhich a plurality of shaving blocks 718 are mounted. Alternatively, theshell 704 may be formed in one-piece with the shaving blocks 718 beingintegrated with the shell base 716. The cap 707 is mounted to the shellbase 716 by a plurality of fasteners 717, (seen only FIG. 39).Alternatively, the cap 707 may be releasably locked to the shell base716 by locking features (not shown) or the cap 707 may be simply fittedon top of the shell 704 temporarily during bone cleaning. The shell base716 includes a bottom 720 that is generally circular in shape. Aplurality of spacers 721 space the bottom 720 from the base 702. Thebottom 720 defines a through bore 722 that is generally centrallylocated within the bottom 720. A bushing 724 is mounted to the bottom720 in the through bore 722 and rotatably supports an agitator 726.

The agitator 726 includes a cross-shaped first end 728 that engages acorrespondingly cross-shaped grooved end 730 of the spindle 710. Theends 728 and 730 mate such that rotation of the spindle 710 results indirect rotation of the agitator 726. The agitator 726 extends from thefirst end 728 disposed beneath the bottom 720, through the through bore722 and upwardly into the void space 706 to a second free end 732. Whenthe cap 707 is attached, the agitator second end 732 is seated in closedend bore formed in cap 707. Cap 707 thus supports the agitator secondend 732.

The agitator 726 is generally cylindrical in shape and is elongatedbetween its ends 728, 732. The agitator 726 includes a stem 734 disposedabout a rotational axis and a pair of fins 736 extending radiallyoutwardly from the stem 734. The fins 736 extend helically about therotational axis from the first end 728 toward the second end 732. Whenbone is placed in the void space 706 the fins 736 rotate to pick up andtumble the bone and press the bone outwardly away from the rotationalaxis of the agitator 726. The fins 736 may be tapered from the first end728 toward the second end 732 such that the fins 736 increase inradially outward dimension from the stem 734 as the agitator 726 extendsfrom the second end 732 toward the first end 728.

Cleaning elements 738 in the form of fluted screws 738 clean soft tissuefrom the bone placed in the void space 706. Axles 740 rotatably supportthe fluted screws 738 in the shaving blocks 718. The axles 740 aresupported and fixed at a first end in the base 702 and extend upwardlyfrom the base 702 to a second end. The second end is disposed in a topopening 742 in a top plate 759 of the shaving blocks 718.

Referring to FIGS. 40 and 41, each of the fluted screws 738 include asleeve 744, a pair of couplings 746, 748 for press-fitting into opposingends of the sleeve 744 to rotate about the axle 740, and a pinion gear750 for engaging the drive assembly 714 of the cleaning head 700. Eachsleeve 744 has an axially extending through bore, (not identified). Eachsleeve 744 is further shaped to have a plurality of flutes 752 thatextend helically around the outer surface of the sleeve. Flutes areformed with adjacent surfaces that meet at defined edges 761 discussedbelow. This flute geometry facilitates gripping and tearing of softtissue from the bone as part of the cleaning process. As shown in FIG.39, each fluted screw 738 is rotatably mounted to a separate one of theshaving blocks 718. Sleeves 744 are preferably formed of stainlesssteel.

Referring to FIGS. 45 and 47, the shaving blocks 718 are preferablyformed of stainless steel. The shaving blocks 718 are mounted adjacentthe shell base 716 to form part of a generally cylindrical inner surface754 of the shell 704. The inner surface 754 further defines the voidspace 706. Bone is compressed against the inner surface 754 by theagitator 726. Each shaving block 718 includes a ring shaped collar 755.The collar 755 defines an opening 757 that receives the associatedfluted screw 738. A front post 756 extends upwardly from the collar 755to the top plate 759. Top plate is longitudinally supported by a thrustbearing (not illustrated). Post 756 has a front surface 758 forming partof the inner surface 754. An elongated space 760 is defined in the frontpost 756 to receive the fluted screw 738. The fluted screw 738 rotatesin the elongated space 760 in the front post 756. A portion of thesleeve 744 extends radially inwardly toward the agitator 726 a distanceaway from the front surface 758 to grip soft tissue attached to bonedisposed in the void space 706.

Each sleeve flute 752 is shaped to define a pair of cutting edges 761disposed on opposing sides of the elongated space 760 (see FIG. 47).These cutting edges 761 are sharp enough to cut soft tissue that theassociated sleeve 744 grips or captures during rotation. Each sleeve 744engages the soft tissue still attached to bone and impinge that softtissue against the cutting edges 761 during rotation to cut the softtissue away from the bone. The agitator 726 forces the bone with softtissue attached thereto toward the sleeves 744 to facilitate gripping ofthe soft tissue by the fluted screws 738 and corresponding cutting ofthe soft tissue by the cutting edges 761. Fluted sleeves 744 alsoseparately act to cut the soft tissue from the bone although to alimited extent.

A plurality of wire brushes 762 are fixed to each shaving block 718 toclean the associated fluted screws 738. In the embodiment shown two wirebrushes 762 are attached to each shaving block 718. Each brush 762 has afirst end 764 fixed to the top plate 759 of the shaving block 718 and asecond end 766 disposed adjacent the base collar 755. A plug 763 (seeFIG. 46) is inserted into an opening 765 in the top plate 759 of theshaving block 718. The first end 764 of the wire brush is press fit intoa bore 767 in the plug 763. The plug 763 is press fit into the opening765 and snugly holds the first end in the opening 765 so that thebrushes 762 remain fixed relative to the rotating fluted screws 738.

Referring to FIG. 39, each of the wire brushes 762 includes an elongatedcylindrically shaped substrate 777 formed of metal or a sterilizableplastic such as a glass-filled nylon. The bristles 768 are preferablymade of metal such as stainless steel. The bristles 768 clean out softtissue trapped in the flutes 752 of the fluted screws 738 as the flutedscrews 738 are rotating in the void space 706. Accordingly, the bristles768 are positioned such that they penetrate into the flutes 752 of thefluted screws 738. The bristles 768 remain fixed to the shell 704 whilethe rotating flute screws 738 rotate relative to the shell 704 and thefixed bristles 768.

As previously discussed, the hole 708 extending through the base 702 isoccupied by spindle 710. The spindle 710 extends from the first end 730that engages the first end 728 of the agitator 726 to a second end 770having features (such as a square shaft configuration) for mating with adrive system such as a drive motor (shown but not numbered). In theembodiment shown, the drive assembly 714 further includes a pinion gear772 that is fixedly mounted to the spindle 710. The gear 772 is adaptedto mate with the gears 750 of the fluted screws 738 to transmit power tothe screws 738. This causes the fluted screws 738 to rotate when thedrive system is actuated. Simultaneously, the spindle 710 also transferspower from the drive system to the agitator 726 so as to rotate theagitator. Alternatively, the first end 728 of the agitator 726 and thegear 772 could be configured to engage and be rotatably fixed to thebase unit spindle head 108 via the alignment pin 110 and teeth 112 so asto be operated by the base unit 52.

In the embodiment shown, the gear ratio of the gear 772 to gears 750 is1:1. In alternative embodiments, different gear ratios could be employedsuch as 1:2 or 1:3 and vice versa depending on the particular desiredrelative rotational speeds of the agitator 726 and fluted screws 738.

During operation, uncleaned bone is first placed in the void space 706for cleaning and the cap 707 is then placed to cover the void space 706.The uncleaned bone includes soft tissue attached thereto that requiresremoval prior to processing by the mill head 60. The drive system orbase unit 52 (if the cleaning head 700 is mounted to the base unit 52)is then actuated to start rotation of the drive assembly andsimultaneous rotation of the agitator 726 and fluted screws 738. Theagitator 726 then acts to tumble the bone and forces the bone againstthe fluted screws 738. The fluted screws 738 grip soft tissue attachedto the bone and cut the soft tissue away from the bone either by thenature of the flutes 752 on the fluted screws 738 or by impinging thesoft tissue against the cutting edges 761 of the shaving blocks 718. Thewire brushes 762 continuously act to clean the fluted screws 738 byremoving material out from the flutes 752. Once the cleaning head 700has sufficiently removed soft tissue from the bone, the cap 707 isremoved and the cleaned bone is grabbed by forceps or other device forfurther processing. The cleaning head 700 may then be cleaned ordiscarded.

While not illustrated, it should be understood that RFID 270 and coil271 (FIG. 5) may be embedded in the base 702 of cleaning head 700. Thedata in RFID 270 are used by control console 66 to regulate theoperation of the system base unit 52 when cleaning head 700 is attached.

XI. Fourth Alternative Cleaning Head

Referring to FIGS. 48 and 49, a fourth alternative cleaning head 800 isnow described. Cleaning head 800 includes a base 802. A shell 804 ismounted to the base 802. The shell 804 defines a void space 806 forreceiving the bone to be cleaned. A pair of shields 805 are fixed to thebase 802 on opposing sides of the shell 804. A cap 807 is mounted toeach of the shields 805 above the shell 804 to cover the void space 806.The base 802, shell 804, and cap 807 can be formed from the samematerial from which the shells 192 and 194 of head 56 are formed.Alternatively, if cleaning head 800 is a use-once unit, base 802, shell804, and cap 807 may be formed from a sterilizable plastic such as apolycarbonate plastic.

The base 802 is shown in FIGS. 48 and 49 as being rectangular in shapewithout any features for engaging the base unit 52. Accordingly, thecleaning head 800 may be a stand-alone unit for cleaning bone in whichthe base 802 is simply attached to a separate drive system (shown butnot numbered). However, in alternative embodiments, the cleaning head800 is operated by the base unit 52. In these embodiments, the base 802has an outer diameter that allows the base 802 to be slip fitted withinthe circular void space defined by the base unit lip 78. In this case,like the second alternative cleaning head 630, the base 802 is circularin shape and four equiangularly spaced notches (not shown) extendupwardly from the bottom of the base 802 around the outer perimeter ofthe base 802. The notches receive the pedestal teeth 84 when thecleaning head 800 is seated on the base unit 52. A groove (not shown),like groove 642, extends inwardly around the circumferential outersurface of the base 802. Base 802 is further formed with twodiametrically opposed notches (not shown), like notches 644 (one shownin FIG. 32) that extend inwardly from the outer circumferential surfaceof the base 802. Each notch being dimensioned to receive a separate oneof the fingers 88 integral with the base unit retention arms 86.

Referring back to the embodiment of FIGS. 48 and 49, the base 802 has athrough hole 808 that extends top-to-bottom through the base 802. Thehole 808 is centered along the top to bottom longitudinal axis of thebase 802. The hole 808 is occupied by a spindle 810. The spindle 810forms part of a drive assembly of the cleaning head 800. The spindle 810is rotatably supported in a bearing 812 mounted to the base 802. In thealternative embodiments in which the cleaning head 800 is operated bythe base unit 52, the spindle 810 is not present and the hole 808 isdimensioned to allow the base unit spindle head 108 to freely movetherein and engage the cleaning head 800.

Referring to FIG. 48, the shell 804 includes an outer basket 814 and aninner basket 816 spaced from the outer basket 814 to define a gap 818therebetween. In the embodiment shown, the outer 814 and inner 816baskets are fixed to one another and to the spindle 810 such thatrotation of the spindle 810 results in rotation of both of the baskets814, 816. Outer basket 814 has a bottom 820 with an annular cavity 822defined therein for receiving a circular plate 824 of the spindle 810.The circular plate 824 is secured to the outer basket 814 with fasteners(not shown). The base 802 defines a pocket 807 for receiving the bottom820 of the outer basket 814. A pair of washers 821 with roller bearings(not shown) disposed therebetween are seated in the pocket 807 betweenthe base 802 and the outer basket 814 to rotatably support the outerbasket 814 for rotation relative to the base 802. Shields 805 protectusers from the rotating shell 804.

The inner basket 816 has a bottom plate 826. A tube-shaped sleeve 828extending upwardly from plate 826. Sleeve 828 has an open end 830through which the bone to be cleaned is deposited in the basket 816.Sleeve 828 includes a plurality of openings 832. Each opening 832 isdefined by a raised, inwardly directed scallop (not illustrated). Eachscallop, which is similar to mill element scallop 336, has a sharp edge,that defines the adjacent opening 832. Thus, the opening 832-definingscallops give the sleeve 828 a shape similar to that of a grater. Here,since the scallops are inwardly directed, towards the longitudinal axisof the basket, the inner wall of the sleeve 828 is the grating surfaceof the inner basket 816. The openings 832 are sized and configured to besmall enough to prevent the bone from falling therethrough, but largeenough to grasp or at least partially capture and temporarily hold thebone and tumble the bone about an inner surface 834 of the inner basket816. The plate 826 may include similar openings in alternativeembodiments, but is solid in the embodiment shown.

A cleaning element 840, in the form of a brush 840, is rotatablysupported in the void space 806 for engaging the bone tumbling againstthe inner surface 834 of the inner basket 816. The brush 840 has a firstend 842 disposed outside of the void space 806 and a second end 844disposed inside the void space 806. The brush 840 includes an elongatedcylindrically shaped substrate 846 formed of metal or a sterilizableplastic such as a glass-filled nylon. Bristles 848 are attached to thesubstrate 846 by an adhesive 847 such as an epoxy adhesive. Inmanufacture, adhesive 847 is initially applied over an outer cylindricalface of substrate 846. Before the adhesive cures, the bristles 848 areplanted in the adhesive 847. The bristles 848 are preferably made ofmetal such as stainless steel. The bristles 848 grab and tear softtissue from the bone while the bone is frictionally grabbed by the innerbasket 816 via the openings 832. Soft tissue that is removed by theopenings 832 is captured in the gap 818 between the outer 814 and inner816 baskets. In FIG. 48 the brush 840 is shown generally centrallydisposed in the void space 806 for rotating about a central axis. Inother embodiments, the brush 840 is disposed about an axis offset fromthe central axis of the void space 806 and the brush 840 can likewise bedisposed at an acute angle to the shell 804.

As previously discussed, the hole 808 extending through the base 802 isoccupied by the spindle 810. The spindle 810 extends from the circularplate 824 to an end 850 having features (such as a square shaftconfiguration) for mating with a drive system such as a drive motor(shown but not numbered). In the embodiment shown, the spindle 810 isrotatably fixed to both the outer 814 and inner 816 baskets to transmitpower from the drive system to the baskets 814, 816 thereby causing thebaskets 814, 816 to rotate when the drive system is operational.Alternatively, the circular plate 824 could be configured to engage andbe rotatably fixed to the base unit spindle head 108 via the alignmentpin 110 and teeth 112. As a result, the cleaning head 800 could beoperated by the base unit 52.

In the embodiment shown, a separate drive system (shown but notnumbered) engages the first end 842 of the brush 840 to rotate the brush840 in the void space 806. The separate drive system rotates the brush840 in a direction opposite the direction of rotation of the baskets814, 816. Alternatively, the brush 840 could rotate in the samedirection as the baskets 814, 816, either at the same rotational speedor at different rotational speeds. This separate drive system could be astationary head fixed to the base 802 above the void space 806 with amotor disposed in the stationary head above the void space 806.

In other embodiments the same drive system rotating the baskets 814, 816also rotates the brush 840. Referring to FIG. 49A, in such anembodiment, the spindle 810 a could be offset from the center of theshell 804 a and include a pinion gear 860 that engages teeth 862 in theannular cavity 822 a defined in the bottom wall 820 a to rotate theouter 814 a and inner 816 a baskets. A separate pinion gear 864 isattached to the first end 842 a of the brush 840 a. Thus, when thespindle 810 a rotates in a first direction, the outer 814 a and inner816 a baskets also rotate in the first direction, while the brush 840 arotates in a second direction, opposite the first direction. Thus, thespindle 810 a, gear 860, teeth 862, and gear 864 would form a driveassembly of the cleaning head 800. The gear ratio between the gears 860,864 and teeth 862 are selected such that the rotational speed of thebrush 840 a is substantially faster than the rotationally speed of thebaskets 814 a, 816 a. In some cases the rotational speed of the brush is5,000 to 10,000 RPM and the rotational speed of the baskets 814 a, 816 ais less than 1000 RPM, often less than 500 rpms, and possible 100 rpmsor less. Thus, the ratio of rotational speeds of the brush 840, 840 a tothe baskets 814, 814 a, 816, 816 a is from about 5:1 to about 100:1.

During operation, uncleaned bone is first placed in the void space 806for cleaning and the cap 807 is then placed to cover the void space 806.The uncleaned bone includes soft tissue that requires removal prior toprocessing by the mill head 60. The drive system or base unit 52 (if thecleaning head 800 is mounted to the base unit 52) is then actuated tostart rotation of the spindle 810, 810 a and subsequent rotation of theshells 814, 814 a, 816, 816 a. If the brush 840 a is connected to thespindle 810 a, then rotation of the brush 840 a is also actuated.Alternatively, the brush drive system is actuated simultaneously torotate the brush 840 in a direction preferably opposite to the baskets814, 814 a, 816, 816 a. The inner basket 816, 816 a and the openings 832in the inner basket 816, 816 a operate to grab and tumble the bone. Thebristles 848 of the brush 840, 840 a grip and tear away soft tissueattached to the bone. Once the cleaning head 800 has sufficientlyremoved soft tissue from the bone, the cap 807 is removed and thecleaned bone is grabbed by forceps or other device for furtherprocessing. The cleaning head 800 may then be cleaned or discarded. Insome cases only the inner basket 816, 816 a and the brush 840, 840 a isdiscarded while the remaining components are sterilized and reused.

While not illustrated, it should be understood that RFID 270 and coil271 (FIG. 5) may be embedded in the base 802 of cleaning head 800.

XII. Fifth Alternative Cleaning Head

Referring to FIGS. 50 and 51, a fifth alternative cleaning head 900 isnow described. The cleaning head 900 comprises a base 902. A ring-shapedsection 904 of the base 902 protrudes upwardly from a bottom section 905of the base 902. A cavity 906 is defined radially inwardly from theprotruding ring-shaped section 904. A shell 908 is mounted to the base902 about the ring-shaped section 904 and above the cavity 906 using aplurality of fasteners 907. The base 902 and shell 908 can be formedfrom the same material from which the shells 192 and 194 of head 56 areformed. Alternatively, if cleaning head 900 is a use-once unit, base 902and shell 908 may be formed from a sterilizable plastic such as apolycarbonate plastic.

The bottom section 905 of the base 902 is shown in FIGS. 50 and 51 asbeing rectangular in shape without any features for engaging the baseunit 52. Accordingly, the cleaning head 900 may be a stand-alone unitfor cleaning bone in which the base 902 is simply attached to a separatedrive system (shown but not numbered). However, in other embodiments,the base 902 is attached to the base unit 52 for operation by the baseunit 52. In this case, the base 902 has an outer diameter that allowsthe base 902 to be slip fitted within the circular void space defined bythe base unit lip 78. Like the second alternative cleaning head 630, thebase 902 is circular in shape and four equiangularly spaced notches (notshown) extend upwardly from the bottom of the base 902 around the outerperimeter of the base 902. The notches receive the pedestal teeth 84when the cleaning head 900 is seated on the base unit 52. A groove (notshown), like groove 642, extends inwardly around the circumferentialouter surface of the base 902. The base 902 is further formed to havetwo diametrically opposed notches (not shown), like notches 644 (oneshown in FIG. 32) that extend inwardly from the outer circumferentialsurface of the base 902. Each notch being dimensioned to receive aseparate one of the fingers 88 integral with the base unit retentionarms 86.

Referring to FIG. 51, it can be seen that base 902 has a through hole909 that extends top-to-bottom through the base 902. The hole 909 iscentered along the top to bottom longitudinal axis of the base 902. Thehole 909 is occupied by a spindle 910. The spindle is rotatablysupported by bearings 912 mounted to the base 902. The spindle 910 formspart of the drive assembly of the cleaning head 900. In embodiments inwhich the cleaning head 900 is attached to the base unit 52, the spindle910 is not present and the hole 909 is dimensioned to allow the baseunit spindle head 108 to freely move therein and engage the cleaninghead 900.

Cleaning head 900 includes a rotating grater disc 914 that functions asthe cleaning element. Grater disc 914 is preferably formed of stainlesssteel. The grater 914 is disc shaped and has openings (not identified)around the center of the disc. The openings are positioned and shaped toengage the teeth integral with spindle plate 916, (teeth notidentified). The engagement of disc 914, along with disc 918, to thespindle 910 causes the discs to rotate in unison with the spindle. Areinforcing disc 918 is disposed between the circular plate 916 and thegrater disc 914. Grater disc 914 includes a plurality of openings 920configured to file away soft tissue from bone. Reinforcing disc 918includes larger openings 922 sized to allow filed off pieces of softtissue to fall therethrough and out of the cleaning head 900 via a chute924 in the base 902. Both discs 914, 918 are rotatably fixed to thespindle 910 to rotate with the spindle 910.

Grater disc openings 920, seen best in FIG. 51A, are arranged in arcuategroups on the disc 914 that are angularly spaced apart from each other.Thus, grater disc 914 has a number of arcuate sections that are free ofopenings 920. This increases the mechanical strength of the grater disc914. The sections of the grater disc 914 in which openings 920 areformed extend over the sections of reinforcing disc 918 in which largeropenings 922 are located. Thus, the grated off tissue falls through bothgrater disc openings 920 and reinforcing disc openings 922. Thedimension(s) of the openings 920 are such that the soft tissue anddebris present on the uncleaned bone is filed away and removed to cleanthe bone, but the bone itself is not damaged or diminished beyond ausable state. In other words, the openings 920 are sized and configurednot to result in milling the bone like the mill element 62 of the millhead 60. In one embodiment, the openings 920 are rectangular in shapewith a larger length than width (see FIG. 51A). In a more specificembodiment, the openings 920 are 0.39 cm (0.1 inches) or less long by1.3 cm (0.5 inches) or less wide. Adjacent openings 920 are spaced inparallel columns and rows with approximately 0.2 cm (0.08 inches) orless between rows and 0.1 cm (0.04 inches) or less between columns.

While not identified, it is seen from FIG. 51A that grater disc 914 isformed with a number of arcuately spaced apart and radially outwardlyextending tabs. During the assembly of disc 914, grater disc 914 isplaced over reinforcing disc 918. The grater disc tabs are bent over andagainst the exposed face of the underlying reinforcing disc 918. Thetabs hold discs 914 and 918 together as a unitary assembly.

An opening 926 is defined through the shell 908 above the grater disc914. A plunger housing 930 is mounted to the shell 908 around theopening 926 using a plurality of fasteners 907 a. Plunger housing 930has a chute 932 that defines a plunger passage 934. One end of chute 932extends into and around the outer perimeter of shell opening 930. Aflange 936 extends outwardly from the chute above the end of the chutedisposed against shell 908. The flange 936 is mounted to the shell 908.Chute 932 defines a void space 938 above shell opening 926 for receivingthe bone stock to be cleaned. A cap 915 covers the plunger passage 934.

A plunger 940, seated in chute 932 presses the bone against the graterdisc 914 to facilitate removal of soft tissue from the bone. The plunger940 includes a plunger head 942 that is sized with an outer perimeterslightly smaller than the inner perimeter of the plunger passage 934 toslidably fit in the plunger passage 934. A shaft 944 has a first end 946fixed to the plunger head 942. A handle 948 is fixed to a second end 950of the shaft 944. The shaft 944 extends from the plunger head 942 in thepassage 934 to handle 948. Shaft 944 extends through and is able toslide within cap 915.

A spring 952 is disposed about the shaft 944 between the cap 915 and theplunger head 942. Spring 952 urges the plunger head 942 downwardlytoward the bone to press the bone against the grater disc 914. Theplunger 940 is either manually or automatically operated.

As previously discussed, the hole 909 extending through the base 902 isoccupied by the spindle 910. The spindle 910 extends from the circularplate 916 to an end 960 having features (such as a square shaftconfiguration) for mating with a drive system such as a drive motor(shown but not numbered). In the embodiment shown, the spindle 910 isrotatably fixed to both the discs 914, 918 to transmit power from thedrive system to the discs 914, 918 thereby causing the discs 914, 918 torotate when the drive system is operational. Alternatively, in theembodiments in which the cleaning head 900 is mounted to the base unit52, the spindle 910 is not present and the discs 914, 918 engage and arerotatably fixed to the base unit spindle head 108 via the alignment pin110 and teeth 112.

During operation, uncleaned bone is first placed in the void space 938for cleaning and the cap 915 is then placed to cover the void space 938.The uncleaned bone includes soft tissue attached thereto that requiresremoval prior to processing by the mill head 60. The drive system orbase unit 52 (if the cleaning head 900 is mounted to the base unit 52)is then actuated to start rotation of the spindle 910 and subsequentrotation of the discs 914, 918. Spring 952 presses the plunger 936downwardly so that the plunger head 942 presses the bone against thegrater disc 914. The grater disc 914 relies on the scallop edges thatdefine the openings 920 to cut away the soft tissue from the bone.

During operation of the mill head 900, the user periodically pulls onhandle 948 in order to overcome the force of the spring 952 that holdsthe plunger head 952 against the bone. The bone stock then rotates withthe discs 914 and 918. Almost as soon as the bone stock rotates, thebone presses against the interior wall of the shell 908 that definesopening 926. This abutment of the bone stock against the shell and therotation of the underlying grating disc 914 causes the bone to tumble inthe opening 926. When manual force on the plunger 940 is released,spring 942 causes the plunger head 942 to return to its position againstthe bone. Since the bone has tumbled, at this time a different surfaceof the bone should be pressed against the grating disc for cleaning.

Once the cleaning head 900 has sufficiently removed soft tissue from thebone, the cap 915 is removed and the cleaned bone is grabbed by forcepsor other device for further processing. The cleaning head 900 may thenbe cleaned or discarded. In some cases only the discs 914, 918 and theplunger 940 is discarded while the remaining components are sterilizedand reused.

Again, RFID 270 and coil 271 (FIG. 5) may be embedded in the cleaninghead base 902 to perform their previously defined functions.

Also, alternative structures may be employed to sequentially andrepetitively press the bone against the grating disc 914 and tumble thebone so that each surface is pressed against the disc. For example, insome versions of the invention, spring 946 may be eliminated. In theseversions of the invention, when the cleaning head 900 is actuated, thetechnician performing the cleaning operation will repetitively depressand retract the plunger 940. The depression of the plunger causes theplunger head 942 to press the bone against the grating disc 914. Theretraction of the plunger 940 allows the bone to tumble. A mechanicaldevice, such as a cam assembly may be used to lift and depress theplunger 940. This mechanical device may be used in versions of theinvention that both include and do not include the spring 946 that actsagainst the plunger 940.

In versions of the invention in which manual force is used to press thebone against the cleaning disc, there may be a mechanism to limit theamount of this force. This may be desirable to minimize the likelihoodthat, due to the bone being pressed against the disc 914, the bone isinadvertently milled. One such force-limiting component may be a springconnected at one end to the cap and at the second end to the plungerhead. This spring is sized such that, instead of forcing the plungerhead against the disc, it holds the head above the disc. Manual force isthen required to overcome the spring force to push the plunger headdownwardly in order to press the bone against the disc. The spring thusattenuates the manual force the technician is able to apply to theplunger head during the cleaning process.

In still another version of the invention, the grating disc 940 may beformed to have one or ribs. Each rib projects upwardly from the surfaceof the disc against which the bone stock is depressed. As the discrotates, the rib/ribs rotate under the bone stock. The movement of a ribunder the bone stock serves to force the bone to at least partiallyrotate, tumble, within the shell opening 926. Again, this version of theinvention may or not include the spring 946 that acts against theplunger 940. Should the spring be present, the spring is selected sothat the spring force exerted can be overcome by the action of a discrib pushing up against the bone.

Alternatively, the grater disc may be formed with one or more flexibletabs. A tab may, for example, be formed in an arcuate section of thedisc that is free from of openings. The surface of the tab anglesupwardly from the opening defining section of the disc. As the discrotates, the bone rides over the inclined surface of the tab. Theflexible nature of the tab allows the tab and bone to at least partiallyovercome any force holding the bone against the grating disc. As thedisc continues to rotate, the bone drops of the elevated edge of thetab. This dropping off, rolling off, of the bone serves to rotate thebone so as to present another surface of the bone against the graterdisc for cleaning.

XIII. Sixth Alternative Cleaning Head

FIGS. 52 and 53 depict a sixth alternative cleaning head 1000. Cleaninghead 1000 is similar to the cleaning head 900 except that the plunger940 is replaced with an impingement plate 1052. Impingement plate 1052compresses the bone against grater openings. The cleaning head 1000comprises a base 1002. A ring-shaped section 1004 of the base 1002protrudes upwardly from a bottom section 1005 of the base 1002. A cavity1006 is defined radially inwardly from the protruding ring-shapedsection 1004. A shell 1008 is mounted to the base 1002 on top of thering-shaped section 1004 and above the cavity 1006. The base 1002 andshell 1008 can be formed from the same material from which the shells192 and 194 of head 56 are formed. Alternatively, if cleaning head 1000is a use-once unit, base 1002 and shell 1008 may be formed from asterilizable plastic such as a polycarbonate plastic.

The bottom section 1005 of the base 1002 is similar to that of base 902bottom section 905 described with respect to FIGS. 50 and 51.Accordingly, the cleaning head 1000 may be a stand-alone unit forcleaning bone in which the base 1002 is simply attached to a separatedrive system (shown but not numbered). Alternatively, base 1002 may alsobe configured for use with the base unit 52 so that the cleaning head1000 is operated by the base unit 52. In this embodiment, the base 1002has an outer diameter that allows the base 1002 to be slip fitted withinthe circular void space defined by the base unit lip 78. Like the secondalternative cleaning head 630, the base 1002 is circular in shape andfour equiangularly spaced notches (not shown) extend upwardly from thebottom of the base 1002 around the outer perimeter of the base 1002. Thenotches receive the pedestal teeth 84 when the cleaning head 1000 isseated on the base unit 52. A groove (not shown), like groove 642,extends inwardly around the circumferential outer surface of the base1002. The base 1002 is formed to have two diametrically opposed notches(not shown), like notches 644 (one shown in FIG. 32) that extendinwardly from the outer circumferential surface of the base 1002. Eachnotch being dimensioned to receive a separate one of the fingers 88integral with the base unit retention arms 86.

Referring back to the FIGS. 52 and 53, base 1002 has a through hole (notshown, but same as the hole 909 shown in FIG. 51) that extendstop-to-bottom through the base 1002. The hole is centered along the topto bottom longitudinal axis of the base 1002. The hole is occupied by aspindle (not shown, but same as the spindle 910 shown in FIG. 51). Thespindle is rotatably supported in bearings (not shown, but same as thebearings 912 shown in FIG. 51) mounted to the base 1002. The spindleforms part of the drive assembly of the cleaning head 1000. In theembodiments in which the cleaning head 1000 is mounted to and operatedby the base unit 52, the spindle is not present and the hole isdimensioned to allow the base unit spindle head 108 to freely movetherein and engage the cleaning head 1000.

A cleaning element 1014 in the form of a rotating grater 1014 isdisposed in the cavity 1006. The grater 1014 is preferably formed ofstainless steel. The grater 1014 is disc shaped and has features forengaging a circular plate (not shown, but same as the circular plate 916shown in FIG. 51) of the spindle to rotate with the spindle. Anreinforcing disc 1018 is disposed between the circular plate and thegrater disc 1014. The grater disc 1014 includes a plurality of openings1020. The perimeter of each opening 1120 is defined by a raised scallop(not identified). The edges of the scallops that define the openingsfile away soft tissue from bone. Reinforcing disc 1018 includes largeropenings 1022 sized to allow filed off pieces of soft tissue to falltherethrough and out of the cleaning head 1000 via a chute 1024 in thebase 1002. Both discs 1014, 1018 are rotatably fixed to the spindle 1010to rotate with the spindle 1010 during operation.

The openings 1020 are preferably confined to circumferentially spacedareas on the grater disc 1014 such that the entire grater disc 1014 isnot formed with the openings 1020. This increases the strength of thegrater disc 1014. These spaced areas coincide with the larger openings1022 in the reinforcing disc 1018 to further facilitate movement of thefiled off soft tissue through the discs 1014, 1018. The dimension(s) ofthe openings 1020 are such that the soft tissue and debris present onthe uncleaned bone is filed away and removed to clean the bone, but thebone itself is not damaged or diminished beyond a usable state. In otherwords, the openings 1020 are sized and configured not to result inmilling the bone like the mill element 62 of the mill head 60. In oneembodiment, the openings 1020 are rectangular in shape with a largerlength than width (see FIG. 51A). In a more specific embodiment, theopenings 920 are 0.39 cm or less long by 1.3 cm or less wide. Adjacentopenings 1020 are spaced in parallel columns and rows with approximately0.2 cm or less between rows and 0.1 cm or less between columns.

An opening 1026 is defined through the shell 1008 above the grater disc1014. A cap 1015 partially covers the opening 1026 to define a voidspace 1017 for the bone. The cap 1015 is mounted to the base viafasteners 1007 with the shell 1008 captured between the cap 1015 and thebase 1002. The void space 1017 in this embodiment is defined radiallyinwardly of the shell 1008, below the cap 1015 and above the grater disc1014. The cap 1015 further has an opening 1030 coinciding with a portionof the void space 1017.

An impingement mechanism is disposed in the opening 1030 above thegrater disc 1014. The impingement mechanism includes a plate 1052 thatpresses the bone against the grater disc 1014. Plate 1052 is flexible.The impingement mechanism includes a block 1045 that is mounted to abracket 1044 by fasteners 1043. Bracket 1044 is fixed to the base 1002by fasteners 1046. Block 1045 is formed with an elongated slot 1048 forreceiving a shaft 1050 to which plate 1052 is mounted. One end of shaft1050 is seated in block slot 1048. Set screws 1049 hold the shaft 1050in a fixed rotational position in slot 1048. The impingement plate 1052is fixed fitted over the second end of the shaft 1050. Set screws 1049allows the angular relationship between the impingement plate 1052 andthe grater disc 1014 to be altered for different applications anddifferent sizes of bone. A secondary cap 1019 extends over block 1045.The secondary cap 1019 is formed with a slot 1021 sized to receive asection of the impingement plate 1052.

As previously discussed, the hole extending through the base 1002 isoccupied by the spindle. The spindle extends from the circular plate toan end (not shown, but same as the end 960 in FIG. 51) having features(such as a square shaft configuration) for mating with a drive systemsuch as a drive motor (shown but not numbered). In the embodiment shown,the spindle is rotatably fixed to both the discs 1014, 1018 to transmitpower from the drive system to the discs 1014, 1018 thereby causing thediscs 1014, 1018 to rotate when the drive system is operational.Alternatively, in the embodiments in which the cleaning head 1000 isoperated by the base unit 52, the discs 1014, 1018 are configured toengage and be rotatably fixed to the base unit spindle head 108 via thealignment pin 110 and teeth 112.

To clean bone stock, the bone is initially placed in the void space1017. Cap 1015 is then placed to cover the void space 1017. The drivesystem or base unit 52 (if the cleaning head 1000 is mounted to the baseunit 52) is then actuated to start rotation of the spindle andsubsequent rotation of the discs 1014, 1018. The bone rotates with thegrater until the bone rotates below the impingement plate 1052, thesurface of the impingement plate that is directed towards the disc 1014.Initially, the impingement plate holds the bone against the grater disc1014. This holding action presses the bone against the cleaning disc sothe disc removes the soft tissue from the bone. However, the impingementplate is flexible. As a result, the disc is able to push the bone belowand across the impingement plate 1052. It should be appreciated thatduring this transit of the bone, the impingement plate flexes. As thebone travels under the impingement plate, the bone is momentarily caughtby the bottom edge of the impingement plate 1052. As the impingementplate 1052 snaps back to the static state, the plate rotates the boneover the grater disc. This presents a different surface of the bone isdisposed against the disc. Once the cleaning head 1000 has sufficientlyremoved soft tissue from the bone, the cap 1015 is removed and thecleaned bone is grabbed by forceps or other device for furtherprocessing. The cleaning head 1000 may then be cleaned or discarded. Insome cases only the discs 1014, 1018 are discarded while the remainingcomponents are sterilized and reused.

XIV. Seventh Alternative Cleaning Head

A seventh alternative cleaning head 1100 is now described by referenceto FIGS. 54 through 56. Cleaning head 1100 includes a base 1102. Aring-shaped section 1104 of the base 1102 protrudes upwardly from abottom section 1105 of the base 1002. A cavity 1106 is defined radiallyinwardly from the protruding ring-shaped section 1004. A shell 1108 ismounted to the base 1102 on top of the ring-shaped section 1104 andabove the cavity 1106. The base 1102 and shell 1108 can be formed fromthe same material from which the shells 192 and 194 of head 56 areformed. Alternatively, if cleaning head 1100 is a use-once unit, base1102 and shell 1108 may be formed from a sterilizable plastic such as apolycarbonate plastic.

The bottom section 1105 of the base 1102 is shown in FIG. 54 as beingrectangular in shape without any features for engaging the base unit 52.Accordingly, the cleaning head 1100 may be a stand-alone unit forcleaning bone in which the base 1102 is simply attached to a separatedrive system (shown but not numbered). However, the base 1102 may beconfigured to be seated in the base unit 52 and operated by the baseunit 52 in other embodiments. In these embodiments, the base 1102 has anouter diameter that allows the base 1102 to be slip fitted within thecircular void space defined by the base unit lip 78. In this case, likethe second alternative cleaning head 630, the base 1102 is circular inshape and four equiangularly spaced notches (not shown) extend upwardlyfrom the bottom of the base 1102 around the outer perimeter of the base1102. The notches receive the pedestal teeth 84 when the cleaning head1100 is seated on the base unit 52. A groove (not shown), like groove642, extends inwardly around the circumferential outer surface of thebase 1102. The base 1102 is further formed with two diametricallyopposed notches (not shown), like notches 644 (one shown in FIG. 32)that extend inwardly from the outer circumferential surface of the base1102. Each notch being dimensioned to receive a separate one of thefingers 88 integral with the base unit retention arms 86.

Returning to FIGS. 54-56, base 1102 has a through hole 1109 that extendstop-to-bottom through the base 1102. The hole 1109 is centered along thetop to bottom longitudinal axis of the base 1102. The hole 1109 isoccupied by a spindle 1110. The spindle 1110 is rotatably supported inbearings 1112 mounted to the base 1102. The spindle 1110 forms part ofthe drive assembly of the cleaning head 1100. In the embodiments inwhich the cleaning head 1100 is mounted to the base unit 52, the hole1109 is dimensioned to allow the base unit spindle head 108 to freelymove therein and engage the cleaning head 1100.

A cleaning element, in the form of a rotating grater 1114 is disposed inthe cavity 1106. Grater 1114 is preferably formed from stainless steel.The grater 1114 is disc shaped and has features for engaging a circularplate 1116 of the spindle 1110 to rotate with the spindle 1110. Areinforcing disc 1119 may be disposed between the circular plate 1116and the grater disc 1114. The grater disc 1114 includes a plurality ofopenings 1120 configured to file away soft tissue from bone. The filedoff tissue thereafter falls through the openings 1120 and out of thecleaning head 1100 through an opening 1124 in the base 1102. The disc1114 is rotatably fixed to the spindle 1110 to rotate with the spindle1110 during operation.

The openings 1120 are preferably confined to circumferentially spacedareas on the grater disc 1114 such that the entire grater disc 1114 isnot formed with the openings 1120. This increases the strength of thegrater disc 1114. The dimension(s) of the openings 1120 are such thatthe soft tissue and debris present on the uncleaned bone is filed awayand removed to clean the bone, but the bone itself is not damaged ordiminished beyond a usable state. In other words, the openings 1120 aresized and configured not to result in milling the bone like the millelement 62 of the mill head 60. In one embodiment, the openings 1120 arerectangular in shape with a larger length than width (see FIG. 51A). Ina more specific embodiment, the openings 1120 are 0.39 cm or less longby 1.3 cm or less wide. Adjacent openings 1120 are spaced in parallelcolumns and rows with approximately 0.2 cm or less between rows and 0.1cm or less between columns.

An opening 1126 is defined through the shell 1008 above the grater disc1114. A cap 1115 partially covers the opening 1126 to define a voidspace 1117 for the bone. The cap 1115 is mounted to the base viafasteners 1107. The shell 1108 is captured between the cap 1115 and thebase 1102. The void space 1117 in this embodiment is defined radiallyinwardly of the shell 1108, below the cap 1115 and above the grater disc1114. The cap 1115 further has an opening 1130 coinciding with a portionof the void space 1117.

A plunger 1140 is moveably mounted to cleaning head 1100. The plunger1140 has a handle 1142 to which, at one end, a head 1114 is attached.The plunger head 1144 is sized slightly smaller and has a shape similarto that of opening 1130 to fit through the opening with minimalclearance. The plunger head 1144 is manually (shown) or mechanically(not shown) reciprocated in the opening 1130 to press bone against thegrater disc 1114. The plunger 1140 is preferably formed of stainlesssteel or sterilizable plastic.

A second cleaning element, a fluted screw 1150 is disposed in the voidspace 1117. A shaving block 1152 rotatably supports the fluted screw1150. The shaving block 1152 is located through another opening 1154 inthe cap 1115. The shaving block 1152 is generally centrally located inthe void space 1117 but in other embodiments may be located about theperiphery of the void space 1117 similar to the third alternativecleaning head 700. Additional fluted screws 1150 may also be employed.In the embodiment shown, the fluted screw 1150 comprises a sleeve 1160defining a through bore 1162. The sleeve 1160 is preferably fixed torotate with the spindle 1110. The sleeve 1160 defines a plurality offlutes 1164 that facilitate gripping and tearing of soft tissue from thebone in the void space 1117 during rotation to clean the bone. Thefluted screw 1150 is preferably formed of stainless steel.

Referring to FIG. 56, the shaving block 1152 is preferably formed ofstainless steel. The shaving block 1152 has a flange 1170 mounted to thecap 1115 about the opening 1154. A wall 1172 of the shaving block 1152extends through the opening 1154 and is suspended slightly above thegrater disc 1114 so as not to disrupt rotation of the grater disc 1114.The spacing between a bottom of the wall 1172 and the grater disc 1114is too small for any bone to pass thereunder. An elongated space 1174 isdefined in the wall 1172 to receive the fluted screw 1150. The flutedscrew 1150 rotates in the elongated space 1174 in the wall 1172. A firstend of the fluted screw 1150 is rotatably mounted to the shaving block1152 while the opposite end of the fluted screw 1150 is fixed to thespindle 1110. A portion of the fluted screw 1150 extends a distance awayfrom a front surface 1176 of the wall 1172 to grip soft tissue attachedto bone disposed in the void space 1117.

Shaving block 1152 is shaped to define a pair of cutting edges 1178disposed on opposing sides of the elongated space 1174 (see FIG. 56).These cutting edges 1178 are sharp enough to cut soft tissue that thefluted screw 1150 has gripped or captured during rotation. In otherwords, the fluted screw 1150 engages the soft tissue still attached tobone and impinges that soft tissue against the cutting edges 1178 duringrotation to cut the soft tissue away from the bone. Plunger head 1144 isdesigned to force the bone toward the fluted screw 1150. As a result ofthe abutment of the bone against the screw 1150, soft tissue attached tothe bone is pressed into the spaces between the flutes. As the screw1150 rotates, the tissue entrained in the screw 1150 is rotated againstthe cutting edges 1178. The continued rotation of the screw with theentrained tissue results in the cutting edges separating the tissue fromthe bone. The sharp edges of the flutes of screw 1150 also separatelycut some soft tissue from the bone although to a limited extent.

The plunger head 1144 is generally box-shaped to correspond to thebox-shaped opening 1130. The shell 1108 has a flat 1180 on an innersurface thereof that corresponds to a first flat side 1184 of theplunger head 1144. Accordingly, when the plunger head 1144 is disposedin the opening 1130, the first flat side 1184 of the plunger head 1144faces the flat 1180 on the inner surface 1182 of the shell 1108 with asmall gap defined therebetween (see FIG. 55). The small gap is sized toprevent bone from entering. Opposite the flat 1180 on the other side ofthe plunger head 1144 is the fluted screw 1150 and shaving block 1152. Agap between a second flat side 1186 of the plunger head 1144 and thefluted screw 1150 is sized to restrictively receive small pieces ofbone. As a result, all of the bone must pass under the plunger head 1144so as to be compressed by the plunger head 1144 against the grater disc1114 to remove soft tissue from the bone or pass between the plungerhead 1144 and the fluted screw 1150 to be grabbed by the fluted screw1150 with the associated soft tissue being grabbed by the fluted screw1150 and cut by the cutting edges 1178.

As previously discussed, the hole 1109 extending through the base 1102is occupied by the spindle 1110. The spindle 1110 extends from thecircular plate 1116 to an end 1190 having features (such as a squareshaft configuration) for mating with a drive system such as a drivemotor (shown but not numbered). In the embodiment shown, the spindle1110 is rotatably fixed to both the grater disc 1114 and the flutedscrew 1150 to transmit power from the drive system to the grater disc1114 and the fluted screw 1150 thereby causing the grater disc 1114 andthe fluted screw 1150 to rotate when the drive system is operational.Alternatively, when the cleaning head 1100 is operated by the base unit52, the grater disc 1114 and the fluted screw 1150 are configured toengage and be rotatably fixed to the base unit spindle head 108 via thealignment pin 110 and teeth 112.

During operation, uncleaned bone is first placed in the void space 1117for cleaning and the cap 1115 is then placed to cover the void space1117. The uncleaned bone includes soft tissue attached thereto thatrequires removal prior to processing by the mill head 60. The drivesystem or base unit 52 (if the cleaning head 1100 is mounted to the baseunit 52) is then actuated to start rotation of the spindle 1110 andsubsequent rotation of the grater disc 1114 and the fluted screw 1150.The grater disc 1114 relies on the scallop edges that define openings1120 to cut away the soft tissue from the bone. The grater disc 1114 andthe plunger head 1144 operate to tumble the bone. The plunger head 1144presses the bone against the grater disc 1114 to enhance the cuttingaway of soft tissue from the bone by the scalloped openings 1120. Thefluted screw 1150 grips soft tissue attached to the bone and cuts thesoft tissue away from the bone either by the nature of the flutes 1164on the fluted screw 1150 or by impinging the soft tissue against thecutting edges 1178 of the shaving block 1152. Once the cleaning head1100 has sufficiently removed soft tissue from the bone, the cap 1115 isremoved and the cleaned bone is grabbed by forceps or other device forfurther processing. The cleaning head 1100 may then be cleaned ordiscarded. In some cases only the grater disc 1114 and plunger 1140 arediscarded while the remaining components are sterilized and reused.

XV. Alternative Embodiments

The foregoing has been directed to specific versions of system of thisinvention. Other versions of the system of this invention may havefeatures different from what has been described.

For example, various features of the versions of this invention may becombined. Thus, in some versions of the invention wherein there is asingle head with both cleaning and milling modules, the cleaning modulemay have a drive assembly that rotates both the lower and upper brushes.

Likewise the features of the invention may be different from what hasbeen described. In some versions of the invention, the cleaning headcleaning elements and mill head mill elements may have common couplingfeatures for engaging to the common drive spindle but different couplingfeatures for holding the cleaning head and mill head to the base unit.

Similarly the cleaning head and mill head may have common couplingfeatures for holding the head to the base unit. These versions of theinvention may then have different coupling features for coupling todifferent drive members integral with the base unit. Thus, instead ofhaving a single drive spindle, the base unit may have separate drivespindles that are driven at different speeds, a first speed for thecleaning head 56 and at a second speed for the mill head 60. A commongear assembly connects both of these spindles to the output shaft ofmotor 54 (shaft not illustrated). In these versions of the invention,the complementary coupling features the cleaning element and millelement are provided may be different from each other.

Similarly, there is no requirement that in all versions of the inventionthe cleaning elements and mill elements be disc shaped members thatrotate around their center axis. In some versions of the invention, forexample, one or both of the cleaning elements or mill elements may betube shaped. A brush so shaped may have a bristles that extend inwardlyfrom the body of the brush. This brush is used by placing the bone stockto be cleaned inside the brush. A mill element so shaped may havecutting edges that emerge from the outer face of the body. The bone ispressed against this surface. The formed chips fall into a catch traylocated within the center of the mill element. The above described brushand mill element are therefore designed to be rotated around the axisthat extends through its central lumen.

Both the cleaning head and mill head of this invention may have featuresin addition to what has been described. For example, the cap associatedwith mill head 56 may be fitted to the post 286 integral with brush 59.This allows the medical personnel to by pressing down on the cap, pressdown on the brush 59. The pressing down on the brush thus increases theforce of the bristles against the bone located between the brushes 58and 59.

The integrated cleaning and mill head of this invention may havefeatures different from the described head 490. For example in someversions of the device, the cleaning module may be statically mounted tothe other components. In these versions of the invention, the movementof a trap establishes a path through the cleaned bone can pass into themilling module. Also, in some versions of the invention, a mechanicalmember may physically displace the cleaned bone so as to effect thetransfer of the cleaned bone to the milling module. In some versions ofthis embodiment of the invention, the trap (or member) that allows(performs) the transfer of the cleaned bone from the cleaning module tothe milling module may be automatically actuated. This would furtherreduce the amount of time the surgical personnel need to devote toperforming and/or monitoring the bone cleaning and bone millingprocesses.

Also, in some versions of the invention, the brush bristles may notalways be of constant height. In some versions of the invention it maybe desirable to construct the lower brush so that the bristles adjacentthe center of rotation of the brush are of lower height than thebristles spaced from the center of rotation. In these versions of theinvention, it may also be desirable to construct the upper brush so itsbristles close to the center of rotation are longer than the bristlesspaced from this axis. It is believed that an advantage of providebrushes having these features is that the bristle arrangement reducesthe extent to which centrifugal force causes the bone stock beingcleaned to move to the outer perimeter of the brushes. By maintainingthe bone stock adjacent the center of the brushes, the likelihood thatthe bone stock becomes trapped between the outer perimeter of thebrushes and surrounding surfaces of the cleaning head housing issignificantly reduced. Should the bone stock become so trapped, theeffectiveness of the cleaning process can be adversely affected.

Likewise it should be understood that in versions of the invention withintegrated cleaning and milling modules, these modules may not beremovable from the base as a single piece unit. In some versions of theinvention the cleaning module and milling modules may be separatelyremovable. After use, each module is independent sterilized, the wornparts replaced, and reattached to the base unit.

It should likewise be appreciated that versions of the system of theinvention can include less than all the described components. Not allversions of the invention may include memories that describe thespecific speeds at which the cleaning elements and mill elements shouldbe driven. This is especially true for versions of the invention whereinthe cleaning elements and mill elements are drive at the same speed.This may also be true for versions of the invention wherein the baseunit has two drive spindles that are geared to operate at differentspeeds.

Some versions of the invention may not include a removable catch trayfor holding the milled bone. Some cleaning heads/modules of thisinvention may only have a single cleaning element. In some versions ofthe invention, the brushes may not have bristles. Instead, each brushhas an abrasive surface that when is rubbed against the bone stock,cleans the bone stock.

Further in some versions of the invention the cleaning head driveassembly that simultaneously rotates brushes 416 and 418 may rotate thebrushes in the same direction. Drive assembly may also be provided thatrotate the brushes or other cleaning elements at different speeds.

Cleaning head 630 may, in some versions of the invention be providedwith a removable retaining ring. This ring has a rim that extends overthe cap rim 684. The ring has a skirt with features that facilitate theremovable coupling of the ring to the base 632. The ring is coupled tothe rest of the head during the cleaning process in order to prevent theinadvertent lifting of the cap away from the underlying base 632 andbrush 58.

Alternatively, cleaning head 630 may be constructed so that the voidspace in which brush 58 is seated has a depth greater than the height ofthe brush.

In some versions of the invention in which the cleaning head is providedwith a cap that is flexed against the brush, the cap may have a handhold. The hand hold may include a cylindrical neck that extends upwardlyfrom the apex of the cap dome. A head, also cylindrical in shape,disposed above the neck and that extends radially outwardly beyond theneck is also part of this hand hold. During the cleaning process, theindividual charged with the cleaning grasps the hand hold to push downon the cap and also move cap so the top of the cap is turned from sideto side. This turning of the cap changes the orientation of the bristlesthat extend downwardly from the cap. This changing of the orientation ofthe bristles can, in some circumstances, improve the efficiency of thecleaning process.

The cleaning head and mill head of this invention may be provided withfeatures other than the disclosed spout 668 and sleeve 308 forfacilitating the coupling of these two heads together as part of thebone transfer process. For example in some versions of the invention,the cleaning head may have a spout that is dimensioned to seat in themill head feed port into which the cleaned bone stock is introduced intomill head.

Likewise it should be understood that while this invention is intendedfor use to clean autograft bone, its applications are not so limited.System 50 of this invention may also be used to clean and mill donorbone, sometimes referred to as allograft bone.

The materials from which the components of this invention are fabricatedmay be different from what has been described. For example, in someversions of the invention, the enter cleaning head, including thehousing-forming shell components may be disposable. In these versions ofthe invention, the components forming the housing, instead of being madeof metal may be made of sterilizable plastic. Likewise, there is norequirement that the brushes always include bristles formed fromstainless steel. The bristles may be formed from other bendable metalsnot prone to breakage such as titanium or alloys of titanium.

The geometry of the components may also vary. For example, in theversions of the invention wherein the cleaning element is disc, thescallops with edges that performing the cleaning function areillustrated as being in sets of arcuately spaced apart clusters. Inalternative versions of the invention, the scallops with edges, andcomplementary openings are formed throughout the whole of the body ofthe disc. There are no scallop and opening free sections of the disc.

It should further be appreciated that the processing steps executed bythe system may be different from what has been described. For example,the cleaning head and mill head memories are described as having flagbits that are set once the head is used. This is to prevent reuse of anunsterilized head for a procedure on a new patient. However, there maybe times when, after an initial amount is cleaned and milled, thesurgeon decides that it is necessary to have additional bone chipsavailable. Accordingly, the software may have an override that allowsthe surgical personnel to, after acknowledging that cleaning head ormill head was used, to reuse the cleaning head. Thus allows thepersonnel to reuse the heads during the same procedure on a singlepatient.

Also, while the invention is described as a combined system for bothcleaning and milling bone, other versions of the invention may notperform both functions. The base unit and cleaning head may form asystem of this invention that is used just to clean bone. The advantageof the system being that it provides a mechanized means of cleaning thebone that substantially eliminates the need for surgical personnel tohold the bone. Also, depending on the system of this invention, it maybe that the cleaning elements are the only disposable portion of thesystem. Depending on the materials forming components from which thissystem is fabricated, this may limit the expenses associated withproviding the system.

Further it should be clear that various ones of the cleaning elementsdescribed above as well as other cleaning elements may be combinedtogether in a single cleaning head.

Also there is no requirement that the system of this invention beconstructed so that first the bone be cleaned and then milled. In someversions of the invention, the bone may initially be milled to formchips of substantially uniform size. These chips are then processed by acleaning head/module. The cleaning head contains cleaning elementsshaped especially to clean the chips of produced by the millhead/module.

Accordingly, it is an object of the appended claims to cover all suchvariations and modifications as come within the true spirit and scope ofthe invention.

What is claimed is:
 1. A system for cleaning and milling bone stock,said system including: a base unit, said base unit having at least onelocking feature for releasably holding a head unit that is separate fromsaid base unit to said base unit; a motor disposed in the base unit; acleaning head separate from said base unit, said cleaning head havingleast one cleaning element moveably mounted within said cleaning headthat, when actuated, cleans bone stock, said at least one cleaningelement including at least one coupling feature shaped to engage acomplementary feature connected to said base unit motor when saidcleaning head is attached to said base unit so that actuation of saidmotor results in actuation of said cleaning element; a mill headseparate from said base unit and said cleaning head, said mill headshaped to be releaseably attached to said base unit, said mill headhaving at least mill element moveably disposed in said mill head, saidmill element having: at least one feature for converting bone stockintroduced into said mill head into bone chips; and at least onecoupling feature shaped to engage with a complementary coupling featureconnected to said base unit motor when the mill head is attached to saidbase unit so that actuation of said motor results in actuation of saidmill element.
 2. The system of claim 1, wherein: said mill head isformed with at least one locking feature for engaging a said lockingfeature integral with the base unit so that said mill head is releasablyheld to base unit; and said cleaning head is formed with at least onelocking feature for engaging a complementary locking feature integralwith the base unit so that said cleaning head is releasably held to thebase unit, wherein said mill head locking feature and said cleaning headlocking feature are shaped to engage the same said locking featureintegral with the base unit.
 3. The system of claim 2, wherein: saidbase unit at least one locking feature for releasably holding a headunit is at least one finger that is moveably attached to said base unit;said cleaning head locking feature is at least one opening formed insaid cleaning head that is positioned to receive the said at least onefinger of said base unit; and said mill head locking feature is at leastone opening formed in said cleaning head that is positioned to receivethe said at least one finger of said base unit.
 4. The system of claim3, wherein said base unit includes a body to which at least one arm ispivotally mounted and said arm is formed to include the said at leastone finger that is said base unit at least one feature for releasablyholding a head unit to said base unit.
 5. The system of claim 1, whereinsaid base unit at least one locking feature for releasably holding ahead unit is an arm that is pivotally mounted to said base unit.
 6. Thesystem of claim 1, wherein said mill element at least one couplingfeature and said cleaning element at least one coupling feature areshaped to engage with the same coupling feature connected to said baseunit motor.
 7. The system of claim 1, wherein: a controller is connectedto said base unit motor to regulate operation of said motor; saidcleaning head includes a data tag that indicates that said head is acleaning head; said mill head includes a data tag that indicates thatsaid head is a mill head; said base unit includes a reader capable ofreading the data in the said memory of the said head attached to thebase unit; and said controller is connected to the base unit memoryreader for receiving the data read by said memory reader: and: when theread data indicates that said cleaning head is attached to said baseunit, said controller causes said base unit motor to be actuated inorder to appropriately actuate said at least one cleaning element; andwhen the read data indicates that the mill head is attached to said baseunit, said controller causes the base unit motor to be actuated in orderto appropriately actuate said at least one mill element.
 8. The systemof claim 7, wherein: said cleaning head data tag is an RFID; said millhead data tag is an RFID; and said base unit reader is capable ofreading data in both said cleaning head RFID and said mill head RFID. 9.The system of claim 1, wherein said at least one cleaning element is oneselected from the group consisting of: a rotating brush; a rotatinggrater; and a rotating fluted screw.
 10. The system of claim 1, whereinsaid cleaning head further includes an agitator mounted in said cleaninghead, said agitator configured to, within said cleaning head, tumble thebone stock.
 11. The system of claim 10, wherein said agitator ismoveably mounted within said cleaning head and, upon the attachment ofsaid cleaning head to said base unit, is connected to said base unitmotor for actuation by said motor.
 12. The system of claim 10, whereinsaid agitator is moveably mounted to said cleaning head and connected tosaid base unit motor to, upon actuation of said base unit motor, rotatewithin said cleaning head.
 13. The system of claim 1, wherein saidcleaning head includes: at least one first cleaning element that ismoveably mounted within said cleaning head that is actuated uponactuation of said base unit motor that is configured to perform a firstcleaning operation on the bone stock; and at least one second cleaningelement disposed within said cleaning head that is different from saidat least one first cleaning element that is configured to perform asecond cleaning operation different from the first cleaning operation onthe bone stock.
 14. The system of claim 1, wherein: said mill head isformed with a feed opening through which bone stock is introduced intosaid mill head; and said cleaning head is formed with a chute whereinsaid chute is shaped to be coupled to said mill head around the feedopening so that bone stock can be transferred from said chute throughthe feed opening into said mill head.
 15. The system of claim 1, whereinsaid mill head mill element includes a plurality of features convertingbone stock into bone chips.
 16. The system of claim 1, wherein: saidmill head includes a first opening through which bone stock isintroduced into the mill head and a second opening through which thebone chips are discharged from said mill head.
 17. The system of claim16, wherein said mill head mill element is located between the mill headfirst opening and the mill head second opening.
 18. A system forcleaning and milling bone stock, said system including: a base unit,said base unit having at least one feature for releasably holding a headunit that is separate from said base unit to said base unit; a motordisposed in the base unit; a spindle connected to said motor to rotateupon actuation of said motor; a cleaning head separate from said baseunit, said cleaning head having least one cleaning element moveablymounted within said head that, when actuated, cleans bone stock, said atleast one cleaning element including at least one coupling featureshaped to engage said spindle so that said actuation of said motorresults in actuation of the cleaning element; a mill head separate fromsaid base unit and said cleaning head, said mill head shaped to bereleaseably attached to said base unit, said mill head having a millelement moveably disposed in said mill head, said mill element having:at least one feature for converting bone stock introduced into the millhead into bone chips; and at least one coupling feature shaped to engagewith said spindle so that actuation of said motor results in actuationof the mill element.
 19. The system of claim 18, wherein: said base unitat least one feature for releasably holding a head unit is at least onefinger that is moveably attached to said base unit; said mill headlocking feature is at least one opening formed in said cleaning headthat is positioned to receive the said at least one finger of said baseunit; and said cleaning head locking feature is at least one openingformed in said cleaning that is positioned to receive the said at leastone finger of said base unit.
 20. The system of claim 19, wherein saidbase unit includes a body to which at least one arm is pivotally mountedand said arm is formed to include the said at least one finger that issaid base unit at least one feature for releasably holding a head unitto said base unit.
 21. The system of claim 18, wherein: a controllerconnected to said base unit motor to regulates operation of said motor;said cleaning head includes a data tag that indicates that said head isa cleaning head; said mill head includes a data tag that indicates thatsaid head is a mill head; said base unit includes a reader capable ofreading the data in the said memory of the said head attached to thebase unit; and said controller is connected to the base unit memoryreader for receiving the data read by said memory reader: and: when theread data indicates that said cleaning head is attached to said baseunit, said controller causes said base unit motor to be actuated inorder to appropriately actuate said at least one cleaning element; andwhen the read data indicates that the mill head is attached to said baseunit, said controller causes the base unit motor to be actuated in orderto appropriately actuate said at least one mill element.
 22. The systemof claim 21, wherein: said cleaning head data tag is an RFID; said millhead data tag is an RFID; and said base unit reader is capable ofreading data in both said cleaning head RFID and said mill head RFID.23. The system of claim 18, wherein said at least one cleaning elementis one selected from the group consisting of: a rotating brush; arotating grater; and a rotating fluted screw.
 24. The system of claim18, wherein: said spindle is connected to said motor to, addition torotating with said motor is able to move longitudinally with respect tosaid motor; and a biasing member is disposed between said motor and saidspindle so as to normally urge a head of said spindle away from saidmotor.
 25. The system of claim 18, wherein: said spindle is formed tohave plural teeth that are located equangularly around an axis aroundwhich said spindle rotates; said cleaning element coupling featureincludes plural openings in said cleaning element positioned to, whensaid cleaning head is disposed over said base, receive the teeth of saidspindle; and said mill element coupling feature includes plural openingsis said mill element positioned to, when said mill head is disposed oversaid base, receive the teeth of said spindle.
 26. The system of claim25, wherein said spindle further includes a pin that is centered aroundthe axis around which said spindle rotates and that projects above saidteeth.
 27. The system of claim 25, wherein said spindle includes foursaid teeth.
 28. The system of claim 18, wherein said at least onecleaning element of said cleaning head consists of: a shaving tube witha window defined by at least one cutting edge; and a fluted screwdisposed for rotation within said shaving tube so that flutes of saidfluted screw rotate adjacent the at least one cutting edge of saidshaving tube.
 29. The system of claim 28, wherein said shaving tube isstatically mounted to said cleaning head.
 30. The system of claim 18,wherein said base unit has a single said spindle that is connected toand rotated by said motor.